Nitrogen padding for Circulating Water System

[rkulisek]

I am currently working on a project involving a Chilled Water Circulating System for a Municipal application. The closed loop system utilizes a series of chillers and pumps (each chiller/pump series in parallel) to cool and distribute the water to the demand-side customers. To dampen the pulsations and account for thermal expansion in the fluid (water @ 60F) we are proposing to install an expansion tank on the suction side of the pumps. In order to do that, we are also going to have to provide make-up water to the tank and nitrogen padding to maintain level and pressure, respectively.

Does anyone have any experience in high pressure (200 psig max) nitrogen blanketing/padding? I am having difficulty locating adequate valves (specifically blanket regulators)for this application.

 

[gr2vessels]

Refer to Appendix E, API 674. There is also software to help the pulsation analysis. Then again, it is a lot easier to ask a fabricator to provide the design and the pulsation dampener for your system, including their guarantee (in lieu of your skin if things go south because of your design).
Howzat,
Cheers,
gr2vessels

 

[rkulisek]

gr2vessels,

Thanks for your advice.

I read over API STD 674, however it only talks about analytical studies of pulsations in the piping system. I am less concerned with the pulsations due to cyclical pumping than with thermal expansion resulting in pressure fluctuations in the system.

I am looking more for a design guide for expansion tanks in circulating water systems.