The Pipeline Shock Prevention People
Pump Start-up surge, Valve closure shock, Pump shutdown back flow bang.
Large vessels for high pressures with matching bladders, diaphragms, gas bags, and bellows, for over a third of a century.

ShockGuard Ltd. offer shock alleviators. | Please phone USA 910-270-2737
We have people not voicemail. | Call toll free 1-888-DAMPERS

Fluid Flow Control Animations
Fluid Flow Control Animations

PisOlator Diaphragm Seals The PisOlator by ShockGuard PisOlator is a Pressure Instrument Isolator aka Diaphragm Seal

PisOlator Diaphragm Seals / Pressure Instrument Isolator

Diaphragm seals enable the use of standard low cost measurement and control instruments. Diaphragm seals isolate pressure instruments from aggressive, corrosive, flammable, pyrophoric, and carcinogens or other dangerous fluids. The ShockGuard PisOlator diaphragm seal saves the use of pressure instruments made from exotic materials.

PisOlator Diaphragm Seals Gauge / Pressure Switch / Transducer PTFE Diaphragm Seal Glass Filled PTFE or Plastic Carbon Steel Support Ring Stainless or Exotic Metal Corrosive Liquid Washers Typically Glycerine Metal Diaphragm O Ring System T

With a diaphragm seal, the pressure of corrosive liquids can be measured or recorded using instruments that are made from standard low cost materials. A diaphragm seal separates the corrosive fluid from an inert fluid that actuates the pressure indicator instrument.

Diaphragm Seal / Pressure Instrument Isolator PiS P.I. Isolator Diaphragm Seal EX / EG GLYCERINE Gauge / Instrument Connection PTFE Plastic Metal 347 Stainless 1/2" NPT or 1/2" BSP System Connection Pressure Instrument Isolator Application: Diaphragm Seals Enable use of standard pressure instrument with highly corrosive and dangerous liquids. Instrument Block 316 SS Polyprop / PVC / Nylon / GTFE / Kynar System Block Alloy 20 / HC 276 / 316 / Titanium / etc. Clamp Plate Clamp Plate Skt. Hd. Cap Screws Nuts Washers Seal Diaphragm Steel A105 Steel A105 Steel Steel Steel GTFE / Viton / EPDM 90 IRH Shore A M-TFE or 347 Stainless

Diaphragm seals enable the use of standard low cost measurement and control instruments.
A transfer barrier enables the pumping of one fluid to produce pressure in another liquid without the mixing of the two.
See also: JumboGuard for Transfer Barrier.


A diaphragm seal is a flexible membrane that seals and isolates an enclosure. The flexible nature of this seal allows pressure effects to cross the barrier but not the material being contained. Common uses are to protect pressure sensors from the fluid whose pressure is being measured. Diaphragm seals (aka chemical seals) are also used to protect a process fluid from the pressure sensor.

Examples of use are: Sanitary processes (food, pharmaceuticals, etc.) where allowing process fluid to accumulate in the pressure port of the sensor would compromise the purity of the fluid (such as milk getting into the pressure port of a pressure gauge and spoiling). Very pure process fluids, where the metal surface of the pressure sensor might contaminate the fluid (such as copper ions from brass leaching into ultra pure water). Pneumatic systems where small changes in pressures must be eliminated, such as those controlling air bearings.

ShockGuard Shock / Surge Alleviators and Accumulators
Water Hammer and Pipeline Shock / Surge Prevention Equipment
STOP Pump start up surge, Valve closure shock, and Shut down back flow water hammer.
Call Toll Free 1-888-326-7377, UK Europe -- 44(0)161-480-9625, or Contact Us Online.

Understanding How it Works
Shock alleviators and shock accumulators do not alleviate shock, nor do surge alleviators and surge accumulators alleviate surge. SurgeGuard, JumboFlex, and Floatolator all work in the same way. They provide a soft place, so that the pump does not have to instantly accelerate all the liquid in the pipe system when it starts. Similarly, they provide a place into which flow can continue, for a time, against increasing resistance, when a a valve has been slammed. In both cases, because time has been increased, peak pressure generation is decreased. In short, they all prevent the peak pressure from being generated. /

Other Important Sites to Help You

Fluid Flow Control The Fluid Flow Control Source Pumps Accumulators Filters Dampers Heat Exchangers Valves Mixers P.I. / Pressure Indicators Controls Meters Vessels