warped liquid lines

[kberg]

I was recently asked to look at a couple of 320 ton york air cooled screw chillers. These chillers are 7 years old and have standard txv's. The liquid lines on all circuits are warped. It looks like it possibly starts right at the outlet of the txv as it enters the evap, and due to a lack of pipe clamps the liquid lines are warped back to the first pipe clamp on each circuit. The pipe clamps are located 10-15 feet from the txv and have at least a couple 90's between the txv and clamps. These chillers are package chillers from the factory and all of the piping is factory. The warping is bad enough that a couple of the txv's are actually on top of each other. I checked operating temps and pressures and saw nothing unusual. I am looking for some ideas on what the problem could be or what caused this. The only thing I can think of is lack of pipe support and the TD on the txv's themselves. Any advise or ideas would be appreciated.

[Yuri B.]

The countries of the former USSR for almost two decades are plagued by stealers of metals (non-ferric ones having preference). If this instance had happened to us, my first think would be that some unaware plunderer had made an unsuccessfull, fortunately, attempt to wrench off a few good pieces of copper pipe.

[Magoo]

Have you discussed problem with manufacturers, they could possibly have a retro fit solution. Copper pipe is very forgiving, but there are limits and something is going to break. Consider a pilot parallel s/v [small ] to reduce pressure differential and stop bang of pipework, with a timer before main s/v opens.

magoo

[kberg]

Have you discussed problem with manufacturers, they could possibly have a retro fit solution. Copper pipe is very forgiving, but there are limits and something is going to break. Consider a pilot parallel s/v [small ] to reduce pressure differential and stop bang of pipework, with a timer before main s/v opens.

magoo

Thank you for the reply, I have had the manufacture onsite but they are also a local mechanical contractor and are reluctant to do any research on the issue. At least thats what I interpreted from thier response. They seemed like they did not want to say too much and suggested that maybe high head pressure in the past caused this. I like youre idea of eliminating the hydraulic hammer from the liquid.
Thanks again.

[Magoo]

Hi Kberg.
Sounds like you mechanical suppliers have had similar issues and would not admit to a problem.
Another option is to drive supply s/v with compressor start and stop, ie , no pump down and stop, so if compressor stops on temp s/v closes, so you end up with HX liquid charge in HX, therefore when compressor starts on temp call the evap is at high pressure, and minimal differntial between / across main solenoid supply valve. Carrier do that for same problem / reasons. Also reduces risk of icing evap and tube failure.
Magoo thinking out loud again.

[Magoo]

Hell I've just noticed that I'm a senior poster. Is someone taking the pi## due to my age or what.
magoo

[nike123]

Hell I've just noticed that I'm a senior poster. Is someone taking the pi## due to my age or what.
magoo

It is better to be senior then starting push Mods (yes, with capital M) all the time (last 2500 posts)!:D