Customer Comments
“Please let your Sales Manager know what a great response we get from our salesman on all our heat exchanger needs. He was at the Plant yesterday morning and quickly got the ball rolling on this repair. You guys have a great team on getting these quotes out and making repairs. Thanks to all for a great service. I deal with a lot of Companies that talk good service, but very few deliver.”
“On behalf of our company, we would like to thank both you and your crew for a job well done on the Heat Exchanger Project. We appreciate the effort and professionalism exhibited by National Heat Exchange. We know the project was on short notice and the time frame to completion tightly scheduled. Without your expertise, our customer’s expectations could not have been met. Our customer has conveyed to us how pleased he was by everyone’s performance. With your help, we believe, the customer has averted a major problem that would have greatly affected his production.”
“Per our phone conversation, the hydrogen cooler cleaning National Heat Exchange performed for us earlier this spring has been a great success. As noted in the attached graphs (see DOCUMENTS), prior to the cleaning we ran with the cooling water control valve wide open and still could not get the gas temperatures as low as we would like. After the cleaning, the cooling water control valve is running in the 20% – 30% open range and the gas temperature is right at the level we desire.
Thank you and your company very much for your support on this project and please pass along our thanks to the crew that performed the cleaning here on site. Their work has provided a great improvement in the cooling capability of the 3 hydrogen coolers. And the crew was a pleasure to work with. Their professionalism, experience, and patience through our set up delays were greatly appreciated.”
“The cleaning of our lube oil coolers was a complete success. Prior to the outage, we were running with a lube oil temp of 130 F (115 F desired ) with both coolers in service, the water control valves wide open and the cooling water at 55 F. After the cleaning we are running with the desired 115 F lube oil temp with one cooler in service, the water control valve 23% open and the cooling water at 64 F.
Thank you very much to you and your team for helping us get our coolers back to cooling the way they should. And please pass along our thanks to the team that was out here for this work. They were very professional and great to work with. They are welcome back at our site any time.”
“Just got finished making a back pressure check on 1G1 exhaust duct. Looks like we have an improvement from the work done last winter on the HRSG gas side cleaning.
GT Inlet air temp = 49 Deg. F.
GT MW load = 79 MW
Combustor Shell Pressure = 149 psi
Exhaust backpressure = 20″ WC – this used to run in the 27 – 30″ WC
range under similar conditions.”
“We are a fossil plant and we also have condensate running through the insides of our tubes. We only inspect the tube if cooling issues arise but I do not recall ever having a problem on the water side. The partition separating the inlet from the outlet sides of the cooling water sometimes will wear and let the some of the cooling water bypass the tubes which would cause a problem with cooling the oil.
This past spring we sent out 2 turbine lube oil coolers to National Heat Exchange. They turned around both coolers in a 10-day outage with little issues. We were going to have them cleaned on-site but NHE talked us out of doing that. It’s much more expensive to have them on site and you are responsible for the removal of the waste water used during cleaning. We made a trip to their facility and they are very capable of cleaning and fabricating coolers. Our only delay was that the drivers have a limited number of hours they can drive without rest. We were delayed 8 hours on one of the coolers leaving the site due to a mandatory rest period. Ask for 2 drivers if you are located far away from their shop. NHE will bring cradles to ship the coolers in.
They use the same process in the shop as they do on-site, they spin the bundles in a closed system tank with multiple spray nozzles utilizing the heavy flow of the cleaning solution. They also elevate the temperature of the cleaning solution to help break up the “crap” in the center of the bundles. The water solution is run through a filter to remove the said “crap” so you are not just pumping it back into the cooler bundles. They also lance clean the inside (water side) of the tubes.”