All of the pressure reducers I have seen work at no pressure - I think you are misreading the specification sheet - the zero drop at zero flow is referring to pressure drop due to flow - not due to the function of the regulator - its sort of like zero voltage drop at zero amps...
The spec sheet on the Wilkins model 500 does say "The assembly shall be of the balanced piston design and shall reduce pressure in both flow and no-flow conditions." I don't think they would sell many if they didn't reduce the pressure under no-flow conditions. Christopher Christopher Freitas Director of Research and Development OutBack Power Systems, Inc. [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> Tel 360 435 6030 Cell 360 202 4239 19009 62nd Ave NE Arlington WA 98223 USA www.outbackpower.com <http://www.outbackpower.com/> ________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Peter Parrish Sent: Sunday, December 07, 2008 3:22 PM To: 'RE-wrenches' Subject: [RE-wrenches] SDHW and High Mains Pressure We are getting ready to install a SDHW system for a customer and we looked at a number of things regarding his current set up. I just posted a question about tankless heaters but I wanted this query to be a separate one. The customer's mains water pressure is 88 psi on a Saturday afternoon and some time over the next 18 hours, the pressure went as high as 96 psi. I understand that 80 psi is the high end of the safe range in general and that 96 psi on a regular basis can/will damage valves and possibly trigger T&P valves on water heaters. At the recommendation of a plumber I know I looked into pressure reducers, specifically the Wilkins/Zurn line. All the Wilkins regulators produce zero pressure drop at zero flow. What good are these products in protecting plumbing systems from high mains pressures at night when pressures tend to be the highest and usage is at a minimum or even zero? Are there products that will prevent system pressures from exceeding a set point (e.g. 60 psi) under any flow condition including zero? - Peter Peter T. Parrish, President California Solar Engineering, Inc. 820 Cynthia Ave., Los Angeles, CA 90065 Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885 CA Lic. 854779, NABCEP Cert. 031806-26 [EMAIL PROTECTED] MESSAGE CONFIDENTIALITY NOTICE: This message (including attachments) is covered by the Electronic Communication Privacy Act, 18 U.S.C. sections 2510-2521, is confidential, and may also be protected by attorney-client or other privilege. If you believe that it has been sent to you in error, please do not read it. If you are not the intended recipient,you are hereby notified that any retention, dissemination, distribution, or copying of this communication is strictly prohibited. Please reply to the sender that you have received the message in error, then delete it. Thank you.
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