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MTM Hydro 1/4" Big Pressure Switch - 210 PSI

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MTM Hydro's Italian Pressure Switches are used in a variety of methods to turn other items in a pressure washing system on or off. Typically, this switch is used for burner control and is activated by a pressure threshold within the unloader where the switch is mounted. As you disengage your gun by releasing the trigger the pressure suddenly spikes within the switch. This increase in pressure will turn the burner off so that you are not constantly heating the pressureized coils with hot water pressure washers. Once the trigger is re-engaged, the pressure drops and the switch will turn the burner back on. A few other items switches may operate would include supply pumps, electric pressure washer motors, electronically controlled chemical injection systems. This 'Big' Pressure Switch has approximately 1" x 3" x 1" dimensions with ratings of 250 V -15 A.

Be sure to review the specification requirements before purchasing any type of switch as O-ring colors indicate activation PSI specific to your machine. The 'Wet' portion of the switch measures a fraction of an inch and therefore requires a lower PSI for activation as you will notice below.

O-Ring Colors indicate the following:

  • Yellow = 115 Activation PSI
  • Blue = 210 Activation PSI
  • Red = 360 Activation PSI
  • Black = 580 Activation PSI
  • You can install this switch in the 'Normally Closed' or 'Normally Open' position depending upon assembly instructions on your pressure washer by connecting two of the three leads (see image).

  • Red = Normally Closed
  • Brown = Normally Open
  • Blue = Common

  •  Related image WARNING

    This product can expose you to chemicals, including DINP and/or DEHP which is known to the state of California to cause cancer or birth defects or other reproductive harm, go to for more information.

    The products we sell are not intended for use in potable water systems and are only for industrial non-drinking water applications.