How To Order A Wasco Switch
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How To Order A Wasco Switch

We know that you need to feel confident in your suppliers, so we're here to help you along the way. The key to making your pressure or vacuum switch selection is likely defined by:

  1. Type of media being sensed

  2. Maximum system pressure

  3. Amperage

  4. Set point/desired activation point

(Ready to specify a switch? Submit a Product Application Worksheet. Tell us your specifications and we'll help you select a Wasco product series)

Although these are key to determining the proper switch for your application, there are some additional inputs that may need to be defined. The following are the basic requirements for selecting the proper pressure or vacuum switch:


Media - What is the fluid or gas that is being sensed? This will allow Wasco to ensure the wetted parts of the pressure switch are compatible with the application.

condensation on a surface

Maximum System Pressure - What is the maximum system pressure that the pressure switch or pressure transducer/transmitter will be exposed to? Is the unit required to still be functional and accurate after exposure to the maximum system pressure?

  1. Proof pressure is the maximum pressure the unit will see and still be required to remain functional and accurate. The maximum proof pressure provides Wasco with the ability to determine how wide or small the deadband will be for a pressure switch.

  2. Burst pressure is the maximum pressure the unit will be exposed to without any rupture of the unit (escape of application media). The unit will no longer remain functional and accurate.

Set Point - This is the specific point at which you would like the pressure or vacuum switch to actuate. Do you want it to actuate when the system is increasing (rising), or decreasing (falling) pressure?

clean room environment

Reset Point - After the switch has actuated, there is a certain amount of “dead space” it takes to reset the switch. This is also known as the “deadband”, or the reset point range. The Cost-Effective Series, High Overpressure Series, and the High Purity Series (see below) deadband will be a function of the maximum system proof pressure and is not adjustable. Wasco has the ability to internally customize the reset point for the P6, P7, P10, and P11 series during the manufacturing process. This is not something that can be adjusted by the end-user.

Electrical Characteristics - What is the maximum amperage at a given voltage that the electrical switch will receive? The electrical amperage capacity cannot be lower than the circuit amperage. The switch is supplied with 3 wires: Common, Normally Open, and Normally Closed. If this is a first time application, we suggest all three wires so you will have the option to Open or Close. Once a final determination is made, Wasco can then make a 2-wire interface or remain with a 3-wire.


Getting Started

Please complete the product application worksheet to receive a quote. If you complete and submit the Product Application Worksheet, we will contact you via email soon. We're happy to assist you in selecting the proper switch series for your application. Still not sure about getting started? Reach out to us.


two people at computer

Overview of Miniature Switch Offerings

Wasco products floating

Cost-Effective Series – Brass and Stainless Fittings:

  • P110 Series 1 - 500 PSIG max.

  • V110 Series 1.6 - 29.5” HG max.

  • P500 Series 2 - 500 PSIG max.

  • V500 Series 2 - 29.5” HG max.

High Overpressure Series:

  • P400 Series 100 - 6000 PSIG max.

High Purity Series:

  • SP120 Series 1 - 500 PSIG max.

  • SV120 Series 1.6 - 29.5” HG max.

  • UHP150 Series 1 - 500 PSIG max.

  • UHP160 Series 1.6 - 29.5” HG max.

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