How To Protect A Pressure Instrument From Pulsations Or Pressure Spikes

In certain applications, it is often unavoidable to experience pressure spikes.  These spikes can often occur when a pump is being turned on or maybe when a valve opens up.  They tend to be very quick (mostly around 1 second or less), but these short pulsations can be detrimental to any pressure instrument you’re using in the line.

Whether the pressure instrument’s range falls within the spike’s pressure or the spike goes over the range of the instrument, damage can be done and can be done quickly.  To help protect the pressure gauge, transmitter, or pressure switch, there are a few, often inexpensive, options to use.  Please note that the below options only work for pulsations or very short spikes (1 second or less).

Pressure Snubber:



A pressure snubber looks similar to a fitting and is installed just like one.  Its mounted in between the instrument and the process connection.  There are mainly two type of pressure snubbers: sintered or piston.  Both essentially accomplish the same thing by slowing down the media before entering the instrument during a pressure spike or pulsation.  For more information on snubbers, please Click Here 

Throttle Screw, Restrictor Screw or Throttle Plug:


Throttle screws (often called restrictor screws or throttle plugs) are very small screws or plugs that fit inside the orifice of the pressure instrument, and the throttle screw itself has a tiny orifice.  The idea behind the throttle screw is to substantially decrease the orifice size going into the pressure instrument.  Decreasing the orifice size slows down the media entering the instrument during a pulsation; almost creating a bottle neck effect.  Throttle screws are very inexpensive to add and often come standard by some companies.  The downside however is because the orifice is so small, the instrument is more prone to clogging if there are solids in the line.  Virtually every pressure gauge Kodiak provides can come with a throttle screw if needed.

Pressure Relief Valve:



Pressure relief valves are small diversion valves mounted in between the instrument and the process gauge.  The relief valve has an adjustable pressure setting on it.  Once the pressure in the line reaches the pressure setpoint on the valve, the valve closes and diverts the pressure through its other orifice or into the atmosphere.  For more information on pressure relief valves, please Click Here