A Former Intern Checks In

This month I was very busy putting the finishing the touches on our first Piping System Fundamentals course in a distance learning format. Last fall we conducted a beta distance learning course with 30 volunteers, and the results were very positive. They liked the freedom of proceeding through the course at their pace, the ability to replay the videos if they had any questions, and the ability to test their knowledge with online quizzes and example problems.

After reviewing the course, we addressed all the concerns of the beta attendees. We also streamlined the process of course development, while integrating the quizzes into the material, and added a new lab feature so the attendees can run virtual fluid test loops using PIPE-FLO® fluid simulation software. The course started on July 7^th and concludes on August 7^th.

The quality of the course is a direct reflection of the dedication, hard work, and the attention to detail of the team that put the course together. I would like to send a thank you out to Morgan H, Lincoln H, and Alek B, the team that is responsible for making the magic happen. Alek is our current intern from South Puget Sound Community College and is doing a fantastic job in producing the course videos.

In a related event, I got a phone call from Jay M, an intern that worked for us in 2002. He was a mechanical engineering student at St. Martin’s College in Lacey, WA (now it’s a University). Jay graduated in June of 2002 and got a job with the Department of Defense at the Puget Sound Naval Shipyard.

Jay asked if he could stop by with a fluids questions. I always like to catch up with our former interns, almost as much as talking about piping systems, so we set up an appointment. He is currently a nuclear test supervisor working on aircraft carriers. He is married, and they have a 2-year-old running around the house. As I showed him around the office, he had plenty of questions about our software development process, customer technical support, and our work with the pump manufacturers.

I then asked him about his job as a test supervisor and the work he was doing for the Navy. Since I was in the nuclear Navy many years ago, I was interested in finding out that they still have the same quality of training and attention to detail as when I was a nuke.

After the tour of our facilities, we started talking about his piping questions. It seems his father-in-law is building a geoduck hatchery in the southern Puget Sound. Geoducks are very large; edible saltwater clams native to the Pacific Northwest. To be successful, they hatch the geoduck eggs in a hatchery and then place the hatchlings in salt water marsh in the Puget Sound where they grow until harvested. Jay said they needed to design a piping system that pumps water from the sound, through a 3,000 ft pipeline to the hatchery located 180 ft above sea level. He knew about our PIPE-FLO® software, but as an intern entering pump curve data he never used the program.

In about 15 minutes, we were able to design his system and select a pump for the application. I then asked how the flow to the facility varies. He said the flow rate ranges from 100 gpm to 300 gpm based on the time of the year and the growing phase of the hatchlings. We then tried two pumps operating in parallel, one sized for 100 gpm and the second pump sized for 200 gpm. We were then able to see how the system operates under the various expected flow conditions. He then took a copy of his piping system model and was able to determine the pumping requirements for the pump supplier. Since his piping system model had fewer than five pipelines, the PIPE-FLO® demo can perform all the necessary calculations.

I then gave him the model and suggested he insert the pump performance data into the PIPE-FLO® model after the supplier makes the pump selection.

All-in-all it was a great day. I got to see how one of our former interns is making a difference, caught up on the US Navy Nuclear Power program, and then help his father-in-law design a piping system to meet his business needs while reducing the operating and capital costs.

Now it’s your turn, if you have any questions or comments, I would enjoy hearing from you. 

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A Darcy's Fable

I just completed an article about a method to arrive at a reasonable design margin for pump selection when my granddaughter came into my office and asked “Pop Pop, can you read me a story?” Before I have an engineer review an article for technical content, I like to pass it by a non-engineer to check for clarity. I figure my granddaughter falls into the non-engineer group. After I had finished, she had a wrinkled brow and looked a little confused. Not to disappoint, I decided it was time for Darcy's Fable.

The Story of the Timid Hunter

Once upon a time in the Mystical Woods lived Poindexter the Timid*. You see Poindexter was a wolf, but not a normal wolf that likes to hunt in packs, he's a loner. Also, Poindexter doesn't like to take chances and always wanted to play it safe and be prepared for any situation that came his way. As a result of his unusual ways, he was always teased by the other wolves in his town. Now don't get me wrong, the other wolves weren’t bullying our main character, it was more of a good natured ribbing (after all, I don't want to give the wolf a bad reputation in fables and stories).

One day a family of bears named Cost started hanging around the wolves’ village. The bear family had a Papa Bear named Ursus the Operator, a Mama Bear named Ursules the Maintainer, and a Baby Bear named Ursus the First. You see, Goldie Locks broke into the Cost’s old house and trashed the joint, so they were out looking for a new place to live.

Once the Cost’s family started hanging around the wolves’ village, their presence drove the elk and deer away. The wolves in the village didn't like this and said "The bears may be bigger than we are, but they have no right to scare away our food." The wolves were getting very agitated when our hero Poindexter the Timid said “Something must be done, and I will make it my spirit quest to drive away the bears.” He saw this as an opportunity to not only to rid the village of the pesky bears but also as a way to improve his street cred with the other wolves.

Poindexter the Timid then started getting ready for battle. He sat down and developed a list of things he needed to drive off the bears.

The first item on the list was a sword. He didn’t know how big the bears in the Cost family were, but he knew bears could grow very large and so he got the biggest sword he could buy. With a 5 foot blade, it could surely slay the largest grizzly bear in the woods. He took the sword home and started practicing. With great difficulty he could pull the sword from its scabbard, swing it around without falling over, and was even able to get a few solid whacks in on a tree trunk.

Next he thought about the bear’s huge teeth and decided to get body armor. So off to the village he went to see Hercules, the local blacksmith /tailor. Poindexter told Hercules that he was going to drive the bears away and needed a thick suit of armor to protect him from the bite of the largest bear. Once the suit of body armor was finished, Poindexter tried it on and liked what he saw.  The only problem was that was very cumbersome, and he had great difficulty walking home.

By the time our hero had all the items on his list, he had accumulated a helmet to protect his head, a large mace to smite the most formidable bear, an archer’s bow to get in a long distance strike, and a host of other lethal weapons he felt were required to his quest.

See if you can find an image of a wolf in armor and a sword on the internet.

When Poindexter the Timid started on his quest all the wolves in the village gathered around to see him off. All was going well until he came to the log bridge over the mighty Green River. Half way over the bridge Poindexter fell into the deep river and sank out of site. The wolves stared in disbelief and were frozen by what they had just witnessed.

The Cost family was out for a walk and saw our hero fall into the river and sink out of site. The three bears sprang into action. They ran to the river and jumped in to rescue Poindexter. Because of all the added weight of the body armor and weapons it was hard for the bears to bring the wolf to the surface. When they finally got him on the bank of the river, it was too late, he had drowned in the Green River and was dead.

Just then, my granddaughter said, “Now I get your article, Pop Pop. When designing a piping system, you need to plan for realistic contingencies. If your design margins are excessive, it’s easy to over design and not meet the process objectives.”

I was all smiles. It was obvious from her remarks she understood the focus of my article. I then asked her what she thought of the story. “Well, the bears were nice. At least Poindexter the Timid wasn’t eaten alive by the bears, you know, Operating Cost, Maintenance Cost, and First Cost.”

* In this story I am referring to the characters “Spirit Names” which is a practice of obtaining a name based on the way the being lives their life.

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Operating on a Pump Curve

As I have often said, the pump curve is the most important document for a fluid piping system. All centrifugal pumps are designed to operate around a Best Efficiency Point (BEP). Operating a pump away from its BEP for extended periods adversely affects the pump’s operating and maintenance cost while causing a reduction in system reliability. 

In this month’s blog, we’ll review the ANSI/HI 9.6.3 Standard for Rotodynamic (Centrifugal and Vertical) Pumps – Guideline for Allowable Operating Region. In addition, we will see how to incorporate pump operating data into manually entered centrifugal pumps to take advantage of these guidelines.

Pumps should be selected so the specified flow rate through the pump should be close to its BEP flow. The Guideline for Allowable Operating Region (AOR) provides some clarity on best practices. Figure 1 shows a typical manufacturer’s supplied pump curve. I have annotated the AOR and Preferred Operating Region (POR) on the pump curve for a 6.125-inch diameter impeller. In addition, the BEP is indicated on the drawing.

Figure 1 – Annotated pump curve showing the various operating regions called out in the ANSI/HI 9.6.3 – Guideline for Allowable Operating Region.

The key landmark used for all pump regions is the pump’s BEP. The design of the pump for both performance and length of service life is optimized for a flow rate close to the BEP flow. At BEP flow the liquid traveling through the pump suction, impeller, and diffuser section has minimal losses. This is because the flow through the pump is relatively uniform and matches the pumps design geometry. 

When the flow rate through the pump moves away from the BEP, the flow through the pump is no longer uniform, resulting in areas of flow recirculation and hydraulic separation. This causes excessive turbulence, hydraulic loss, and increased vibration. All of the items above increase the wear and tear in the pump. 

The guidelines define the POR on each side of the BEP in which the hydraulic efficiency of the pump is not degraded. The POR for most centrifugal pumps range from 70 percent to 120 percent of the BEP flow. Looking at the pump curve shown in Figure 1, with a BEP of 400 gpm, the range of its POR is from 280 gpm to 480 gpm. 

The pump can still be operated outside this range of flows, but its efficiency and hydraulic operation will be adversely affected. The farther the pump is operated away from its BEP, the worse it is for the pump.

The standard has some guidelines for pumps with higher specific speeds as indicated in Table 1. 

Specific Speed		Preferred Operating Region (POR)
Metric	US Customary
≤ 87	≤ 4500	Between 70% & 120% of BEP
> 87	> 4500	Between 80% & 120% of BEP

 

For example, if the specific speed of the pump is greater than 4,500 the guidelines recommend a narrower flow range of 80 to 120 percent of BEP flow. The manufacturer’s provided value of Pump Specific Speed for the pump shown in Figure 1 is 1,490 so it can operate in the wider flow range.

Allowable Operating Region

The AOR provides a wider range of flow outside the POR where the service life of a pump is acceptable.  The limits of the AOR are determined by the pump manufacturer and are based on factors other than efficient operation. The guidelines also state that the pump should not be operated outside regions that are not fully defined by the pump curve (head, efficiency, and NPSH) without consulting with the pump manufacturer. Looking at the pump curve in Figure 1 the shaded yellow area is the Allowable Operating Region for the pump. The red vertical line on the left side of the AOR represents the minimum flow, and the area past the 70 percent iso-efficiency line represents the maximum flow. 

The AOR does not have clear cut guidelines like the POR. Instead the AOR is based on the manufacturers experience and knowledge about their pump operation. Items that the manufacturer may consider when establishing an AOR consists of the hydraulic loads on the bearing life, shaft seal life, internal mechanical contact, shaft fatigue life, thrust reversal, process fluid temperature rise, vibration, noise, power limits, liquid velocity, Net Positive Suction Head available, suction recirculation, and pump size. 

There are no requirements in the guideline for the manufacturer to state the reasons for selecting the pump’s AOR, but it should be well understood that operation of the pump outside the AOR will dramatically affect pump operation. The guidelines provide discussions of each of the above-mentioned concerns for establishing the AOR, but this information is only provided for an understanding of why the limits are established.

Conclusion

The manufacturer’s supplied pump curve is an important document and provides a wealth of information on how to operate the pump efficiently.  It is one thing to have a copy of the pump curve, but the most important information is knowing where each pump is operating on its pump curve.

In PIPE-FLO®, users have the ability to manually enter pump performance data into the program, and it will accurately model pump performance in the system. To learn more about this process, please read our “Using PIPE-FLO® To Simulate and Analyze Data from a Paper Pump Curve” article in the May ESI News Brief.

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What can be done to increase the flow?

After my four-year tour in the US Navy, I went to work for EBASCO Services in New York City. A little history, EBASCO (short for Electric Bond and Share Company) was started by General Electric in 1905 as a holding company to finance electrical utilities. They financed, designed, built, and in some cases operated the power plants for electrical utilities around the world. The company was restructured after the passage of the Public Utility Holding Company Act of 1935. After that, they focused on designing and building power plants and electrical distribution grids. 

In 1982, I was working for EBASCO at WNP-3 for the Washington Public Power Supply System in Olympia WA. As a startup engineer, I was assigned to a crew involved in flushing the lube oil system for the main turbine. After assembling the lube oil system, it must be cleaned of all dirt and debris introduced during the construction process. The flush is a detailed process that has exacting requirements of cleanliness and must be completed before the main turbine can be placed in operation. 

At this time, I was working for EBASCO during the day and developing PIPE-FLO® at night with Carolyn. My boss, Pat McHale, asked if I could look at the various flush paths within the lube oil system to determine the flow rate and resulting fluid velocities. This was the first time PIPE-FLO® was used in a working environment. High fluid velocities are the key to flushing a system of dirt and debris. I simulated the lube oil system with PIPE-FLO® then evaluated the proposed flush paths with the software. Using the results, the flush team discovered ways to increase the flow rate and resulting fluid velocities when writing the flush procedure. 

One of the key items in the lube oil flush is cycling the temperature of the lube oil. Heating and cooling the oil causes the pipes to expand and contract, which helps dislodge construction dirt and debris from the inside pipe walls. The flowing oil carries away the contaminants where a filter removes them. In addition, to help speed up the process an external oil-cleaning skid was designed by the client and used to heat the oil and provide extra filtration. This cleanup skid was connected to the lube oil reservoir and was continually operated during the flush process. 

The oil cleaning skid was designed by the client and consisted of two paths of heat exchanger, filters, pumps, and control valves. An external boiler provided steam to the heat exchangers to heat the lube oil during the heating cycle. During the cooling cycle, the skid still had lube oil flow through the filters but steam was not supplied to the heat exchanger. 

When we started the lube oil flush the system heated up quickly and we got the design flow rate through the system. During the cold cycle, the flow rate was only a quarter of what was expected. Once again, I was asked to look at the system with PIPE-FLO®.  After modeling the system and performing the hot oil calculation, the model confirmed the system was operating as designed. During the cold cycle, the calculated flow rate through the model also correlated with the observed values on the skid.

While building the model, we discovered the heat exchanger was a three-pass heat exchanger. In addition, the control valves on the skid were of a reduced seat design. 

With this information in hand, we had a conference call with the WPPS team that designed the skid along with the manufacturers of the heat exchanger and control valve. In our discussion with the heat exchanger manufacturer, he stated replacing the head of the heat exchanger could change it from a three-pass to a single pass heat exchanger. That change would reduce the head loss across the heat exchanger in the cold condition and would not adversely affect the system under the hot oil condition. We evaluated the system with this proposed change with the model and discovered it would greatly increase the flow rate through during the cold cycle. The system would have to be down for four to five days for the manufacturer to make the changes in the heat exchanger heads. It was decided having the cleaning skid down for that long would influence the schedule. 

We also looked at the control valve. The supplier said that replacing the reduced seated trim with a full-seated trim would increase the flow rate through the valve under the cold oil condition. He stated the full seated valve should still be able to work correctly in the hot oil condition. We modeled that change to the system and discovered the flow rate in the cold condition would be approximately 75% of the design flow rate. As the cleaning skid would only take the system out of commission for two hours, we decided on this option.

The changes were made to the skid system, and the flow rate increased. The lube oil flush took a total of 30 days to complete, which was about 60% of the time on the schedule. The PIPE-FLO® model provided us with the ability to simulate the system, discover what was happening, and try alternatives quickly without great expense. 

Was PIPE-FLO® the reason we were able to save 15 days from our schedule? No, we had an excellent craft on the job site that maintained high cleanliness standards when building the system and the contractor did an excellent job of maintaining clean conditions during construction. We had a well thought out flush procedure, excellent start up engineers who discovered the low flow problem early, and managers who were interested in improving the process. PIPE-FLO® was one tool that helped provide a clear picture with how the system was operating and what could be done to improve the system. Not bad for the first time the program was used on an actual system.

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EOOW on the USS Jack

This blog article is another sea story about my life on the USS Jack SSN 605 a fast attack nuclear-powered submarine.  Initial training required for all officers qualified to operate a naval nuclear power plant is long and challenging.  After six months at nuclear power school in Vallejo, CA, I was transferred to Idaho Falls, ID to qualify on the A1W operational nuclear “prototype”.  Finally qualified as a Nuclear Watch Officer at the prototype, it was off to sub school in New London, CT for six weeks.  After more than a year of training I was assigned to the USS Jack as a “nuke”.

Even though we had just finished over one year of nuclear power training we were not yet ready to stand watch on our new ship until we completed the ship’s qualification.  The requirement to qualify on a new ship applied to both sailors and officers, all the way up to the Executive Officer.  As a brand new “nuke” it took anywhere from 6 to 10 week to qualify as an Engineering Officer of the Watch (EOOW).  A more senior officer with other shipboard experience would be able to qualify for 1 to 4 weeks. 

During the qualification process, you could not stand watch by yourself.  Since you were not able to do your job but were taking up space on the ship, your shipmates provided extra pressure for you to get qualified so you could be added to the watch bill.  You were referred to as a “non-qual” and always encouraged to get hot and get qualified.

The day I walked onboard the USS Jack the Executive Officer provided me with two Qualification Cards (or qual cards), one for EOOW qualifications and the second for submarines.  This blog article concentrates on qualifying as an EOOW on the USS Jack.  The qual card listed the watch stations that I needed to master, the procedures I needed to perform, and the emergency procedures that I needed to be proficient in, along with all the standing orders I was to become familiar with.  In short, it was a checklist of items needed for qualification as EOOW.  I immediately began studying and started getting my card signed off.

Since I was assigned as the M division officer, I reported directly to the Engineering Officer, Lt. Commander Steven Loucks.  On a naval submarine, the engineering office is responsible for all of the ships engineering equipment and has 4-5 division officers reporting directly to him.  He was also the one that determined when you were ready for your oral boards, the last step in qualifying as an EOOW.  Since I reported directly to him and he wanted all his division officers qualified ASAP I got “special attention”. 

Don’t confuse this “special attention” with special treatment, if anything he made sure all his division officers were well qualified.  For example, my first day underway I was training for 16 hours and turned in at midnight for some rest.  At 0200 (referred to as zero two hundred) or 2:00 AM, the Engineer (who was the EOOW of the midnight shift) got me up to perform one of the required operating procedures.  After signing my qual card, he suggested I get some rack time because he assigned me to the 0600 watch under instruction. 

Once I completed the majority of my assignments and had them signed off, (i.e. describe the ships electrical power bus, how the steam turbine operate, etc.) it was time to concentrate on the operational and emergency procedures. 

As the EOOW, you are responsible for all the Watch Standers in the engineering spaces.  For example when starting up the plant after an extended shutdown, the EOOW would need to follow the ships operating procedures to make sure the system started properly.  This required you to direct each Watch Stander to start an operation and report back when completed.  Now as EOOW you were in charge, but you weren’t necessarily the most knowledgeable. I was a Junior Officer with limited experience, and at this point only trained enough to operate the plant safely. Luckily, I could count on an excellent team of Watch Standers that had gone through a similar program and were very proficient in what they did. 

It was the EOOW’s job to know what evolutions were in progress and that all plant operations were performed per the ships operating procedures.  During this time under instruction, your every move was being reviewed by the qualified EOOW on watch, along with the crewmembers actually performing the operations.  They would provide you with suggestions on what you did wrong or how you could improve. This is the information I paid close attention to.

Emergency Procedures were a big part of the training, (reactor SCRAM, or fire in the engine room lower level for example) and they often involved the entire ship.  A group of Watch Standers were observers for the emergency procedures.  They knew what emergency procedure would be done, but the actual watch standards did not know until the procedure started.  (One point we never referred to them as practice or even a drill, all emergency operations were conducted as if the safety of the ship was in the balance.)

All of a sudden, you got the word from a watch stander “fire in the engine room lower level outboard of the port condensate pumps”.  You immediately went into action, as EOOW the first step was to notify the Officer of the Deck (OOD), the Watch Stander directing the operation of the entire submarine.  The OOD would then notify the ship’s Captain.  Everyone on the ship went to their Damage Control Stations. 

Back in the engine room as the EOOW you then performed the immediate actions in the emergency procedures, you had to know these by heart.  After that, you would review the emergency procedures to ensure all initial actions were completed, perform the follow-on actions, start assessing the condition of the fire, and the effect it may have on the operating power plant.  After all, we had a submarine to operate and that requires both electrical power and power to the main turbines to keep the ship operating.  Once the fire was put out and the engineering spaces and the entire ship was back to its normal operation the observers reviewed what they saw and developed their comments. 

After finishing our watch, we would gather and the observers would analyze our performance and let us know what we did wrong.  This was a very humbling process because all the Watch Standers know the procedures and you hate to be the one to make the mistake. 

If you made a big enough mistake the Engineer might assign you to be the instructor for the engineering department training on the emergency procedure you were now proficient in.  It was an excellent way to determine you would never make the same mistake again. 

After completing all the items on your qualification card you went before the review board.  Here a group of qualified Watch Officers, the Engineer, and the Commanding Officer would ask a question and grade your response.  My oral board was after the evening meal and lasted approximately 90 minutes.  The questions ranged from equipment and system knowledge, normal operations, emergency procedures, the ship’s standing orders, and what you would do if something happened.  Many of the questions were based on experiences of the board members. 

After sweating through the oral boards, the board’s deliberations, and their critique of my performance, the Engineer told me I was qualified as EOOW.  He then told me since I was now qualified I was to relieve the EOOW on duty and assume the watch. 

After finishing my walk down of the engineering spaces and shift change with the EOOW I was relieving I sat in the seat as the only officer in the maneuvering space.  I started feeling really accomplished until one of the enlisted Watch Standers said “Mr. Hardee now that you are qualified don’t think you know it all.”  I then realized how much I didn’t know about being a Nuclear Watch Officer. 

I thanked the watch standards in the maneuvering space for their help and assistance in helping me get qualified.  I also stated that they knew my strengths and weaknesses and we had to work together as shipmates to do our job as best we could. 

The next day while performing my watch I discovered that I went full circle.  One of my non-qualified machine mates asked me to check him out on our main turbine.  I asked him how our turbine operated, how it was different than a typical submarine turbine, and asked a round of questions.  I don’t think I was ever as happy as when I signed his qual card as a qualified EOOW.

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Chief Hill and the Portsmouth Nickels

As I have mentioned in past blogs, after graduating from the US Merchant Marine Academy I activated my commission in the US Navy and applied for the US Naval Nuclear Power program. Shortly thereafter, I was interviewed by Admiral Rickover and his team and was directed to attend the US Naval Nuclear Power Training program. 

The second six months of our yearlong training program was to qualify as an Engineering Watch Officer on a nuclear power plant.  The training occurred in an operational prototype or engine room located in the middle of a desert one hour from Idaho Falls, ID.   The training was intensive with 12 hrs. per day attending classes and seminars, standing training watches, getting our qualification cards completed, and participating in the ever present “emergency” drills. 

The prototype staff that trained us “baby nukes” consisted of officers and enlisted men qualified as nuclear watch personnel.  The majority of the training staff had multiple duty assignments on Navy nuclear-powered vessels.  Machinist Mate First Class Steve Hill was one of the training instructors on my training shift.  He had unbelievable knowledge of the equipment, the total system, plant operation, and was an excellent trainer to boot.  As we would say in the Navy, he was “one squared away sailor.” 

After my six months at the prototype I qualified as a Nuclear Watch Officer and was sent to the USS Jack SSN 605, a nuclear-powered fast attack submarine.   I was assigned as the M Division Officer and Main Prolusion Assistant.  I had 20 chiefs and sailors reporting to me and our division was responsible for all the mechanical equipment associated with the nuclear reactor, steam system, and turbine.  After reporting to a ship, you must get qualified on your new ship and get checked out on all the systems and operating procedures.  During my first training watch in the Engine Room Lower Level, I made a comment to the enlisted Watch Stander that it sounded like the condensate pumps were cavitating.  He said that they were designed to cavitate because of the unique nature of our steam plant and condenser. 

After finishing any engineering watch the off going Watch Officer would brief the Engineering Office on what occurred on the watch.  I mentioned that I thought the condensate pumps were cavitating.  He said they were designed to cavitate based on the unique design of our steam plant.  Following standing orders I then gave the Commanding Officer of the submarine a post watch report, again mentioning the cavitating pump.  I was given the same response by the Captain. 

Another ongoing problem with my systems was intermittent tripping of the feed water pumps.  When increasing the ship's speed, an operating feed water pump would vocationally trip on low suction pressure.  The Watch Standers immediate action was to acknowledge the alarm, check the feed water pressure and surge tank level, and if everything checked out ok start another feed water pump.  This happened on an infrequent basis, however it was an aggravating problem that was difficult to troubleshoot. 

After being on the boat for about 8 months I got word that Steven Hill, now a Chief Petty Officer, was being transferred to the Jack as my new Chief of the M division.  I was looking forward to working with Chief Hill again. 

Upon his arrival, he hit the decks running.  During his qualification watch he too noticed the cavitating condensate pumps and asked why these pumps were cavitating.  I gave him the reason that I was told and he said that was a bunch of “bull s**t, no pumps in a submarine were designed to cavitate.”  So the first thing he did was order a work order to disassemble the pump and research the problem. 

During the next refit, we found a handful of metal disks about the size of a nickel with a 1/16 inch hole drilled in the center.  No one knew where they came from or why they were there.  We then checked the suction strainers on the remaining condensate pumps and discovered they had similar disks.  Once removed the condensate pump no longer cavitated. 

The next thing Chief Hill wanted to do was find out what the disks were, where they came from, and how they ended up in the pumps in the first place. After research, it was discovered that they were part of a de-aeration spray header from the submarines condenser used to remove dissolved oxygen from the condensate. The orifice plates (the disks) were pressed into the spray header and over time, they worked out and collected in the condensate pump suction strainers.  This work was originally done in the Portsmouth Naval Shipyard in New Hampshire and from then on, the disks were referred to as “Portsmouth nickels.”

After the cavitation problem on the condensate pump was fixed, the feed water pumps never again tripped on low suction pressure.  It appears that when responding to an increase in speed, the increased flow rate through the feed and condensate pumps, as well as the system must have caused a pressure transit in the feed pump suction piping causing the pump to trip.  There was nothing we could prove, but there was a definite cause-and-effect relationship.

What I learned from this early life experience is that we should never give up on a problem if it doesn’t sound right and to trust our instincts.  I would say the operators in the Naval Nuclear Power program are some of the best in the world.  Regardless of the standard of excellence taught by the Naval Nuclear Power program we still accepted the “it-always-has-been-operating-this-way” approach with this particular problem with our condensate pumps. We were fortunate to have someone like Chief Hill to remind us to never stop looking for the real problem.

 

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Online Training and the Four Lessons I Learned Instructing Them

As I mentioned in previous blogs we have gone through major revisions of our ESI Learning courses to take advantage of the distance learning format.  After working all summer, we decided to conduct a pilot of our new Piping Systems Fundamentals course and had nearly 60 people participate. 

After reviewing the feedback from the pilot participants, we learned a tremendous amount on how to best use this exciting new means of distance learning.  We received plenty of kudos as to the value of the course, as well as learned a lot on adult learning, attendee involvement, and the training tools.  I would like to share with you some of the lessons learned:

1.       Be very familiar with your distance learning software tools

2.       Don’t make major changes right before the course

3.       As individuals, we use many senses to learn

4.       As an instructor, teaching blended classes and engaging students can be challenging

Developing one of these courses is a team effort; two months prior to the pilot start date Delcina joined us at Engineered Software as our Director of Marketing.  With a wealth of experience in building training programs for technology companies she was quickly brought into the project.  If it were not for her efforts, the course would not have been as engaging and the number of pilot participants would not have been as large.   

One recurring comment we had about our Instructor Led Training Classes was that we had a lack of example problems. In the past we simply didn’t develop that many.  With the self-paced distance learning, we created practical examples for each topic, providing the opportunity for attendees to apply their knowledge to real world scenarios.  The more our team talked about these examples the more we wanted them to mirror a college fluids lab.  Before you know it, we had developed a PIPE-FLO® simulation program for use with the course.  The fun part was creating problems to work out by hand, with examples for people to visualize what happens in a system with variations in tank levels, as well as troubleshoot the operation of pump and control valves. 

Additionally, quizzes provide another learning opportunity. Which for adult learning help reinforce subject matter. The first group of questions we developed were simple calculations.  We then started looking at the process of solving an equation and then identified steps that were more complicated.  For example, if the density of water was used in a calculation instead of the prescribed density of the process fluid, a result would be calculated and if the person entered that value they would get partial credit and an idea as to what they did wrong.  Furthermore, each question provides feedback on the correct answer and how it is arrived at.

A disadvantage of any distance learning class is the inability of the attendee to ask questions.  To overcome this limitation we created forums where attendees could post questions and comments. We also scheduled “Office Hours” in which the instructor led a weekly WebEx presentation where we discussed any questions the attendees wanted covered.  Approximately 1/3 of the students attended the Office Hours sessions.  The number of questions asked was surprisingly small, but I knew from conducting a number of Instructor Led Courses in front of a live audience they always had questions on how to read a pump curve.   I decided to use the extra time in the Office Hours to go over the topic of How to Read a Pump Curve live.  The presentation was well received and resulted in a lively discussion.  As a result of the positive feedback we decided to continue the Office Hours each week, along with covering a Critical Topic and a Q&A session on any question dealing with the course. 

During the four weeks of the class we conducted Critical Topics on Reading Pump Curves, a Piping Head Loss Sensitivity study, Control Valve Operation, and Building a Pump System Curve.  These Critical Topics were well received and have since become an integral part of our “Blended” course. 

Now for the dirty little secrets, since we were developing the Labs and Quizzes right before the topic was released we didn’t have the opportunity to review the content.  I would like to send out a special thank you to Pedro, Charles, Andrew, Angel, Andrea, Maria, Deborah, and Charles who pointed out our errors and points of confusion.

The final survey results were extremely positive with over 95% of the attendees saying they would recommend this course to others.  They’re all looking forward to the development of new courses.

For the remainder of the year we are incorporating many of the suggestions you gave us, such as improving the learning value of the Labs and Quizzes.  We are also incorporating a variety of back office improvements that will make it easier for students to register for our courses and streamline the delivery of the course material. 

Rumor around the office is that our marketing department is already working on a Flo-Master blended e-learning course to launch sometime in the second quarter of 2015. Keep an eye on our newsletter to stay updated.

Looking forward to seeing you in an upcoming course.

Ray Hardee

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