Pressure transmitter protection 2

[yesfan]

I am designing a circuit that requires both low pressure (600 psig) & high pressure(6000 psig)transducers to monitor line pressure due to accuracy requirements. The circuit employs a 4-way,3 position directional control valve which will be "cycled" at 5000 psig system pressure at times. I plan to use a Chemiquip PLV5460L "pressure limiting valve" (or gauge saver) to protect the low pressure transmitter. My concern is that the 4-way valve will introduce "sudden" pressure (less than 50 ms)faster than the PLV will close, and consequently damage the LP transducer.
The oil is MIL-PRF-83282 (about 60-70 SUS) and I plan to also provide the 10 micron chemiquip snubber (suggested for the viscosity), but I have no time response data available to me. My question is does anyone out there have experiance with this situation, and if so, what "proven" gauge saver have you used successfully?

 

[JLSeagull]

I do not believe in gauge savers or snubbers.

Consider checking with the common pressure transmitter manufacturers. Some have ranges that cover your requirements with no protection needed.

I think that Emerson (Rosemount) 3051 series transmitters can be ranged from as low as 0-40 psi and as high as 0-4000 psi in the same model with the body rated 6000 psig. Both gauge and absolute range models exist. The gauge pressure transmitters are also available with ranges to 10,000 psig but lack the 100:1 calibration turndown of the lower pressure model.

Dynisco Viatran also offer transducers or transmitters rated to 15000 psig that can be calibrated with your ranges.

If you need fast response (faster than 100 ms) you should define this before contacting these organizations.

 

[yesfan]

Thank you for the reply JL Seagull. However I have chosen 0.1% F.S.Sensotec units because I am bound to measure down to 0-150 psi(+/-1), as well as up to 5500 psi (+/-10)within the same circuit. I can not meet the measurement accuracy requirements with a single range unit.

 

[danw2]

Ray Snubber seems to be the only vendor I've found who offers response data.

http://www.stewartsusa.com/index_files/snubbers.htm

The Ray Snubber Fact Sheet

http://www.stewartsusa.com/index_files/Ray_Snubber _Fact_Sheets.PDF

has a graph on page 4 for selecting a snubber with an appropriate sized piston for various pressure ranges and media viscosities.

 

[yesfan]

Thanks danw2, This is exactly the type of info I was lookinf for. I have contacted Ray Snubbers directly and await their recomendation.