PLAST-O-MATIC SWT Pressure Switches

Descriptions of PLAST-O-MATIC SWT

• The Plast-O-Matic Series SWT Pressure Switch can be used to activate or de-activate equipment when pressure in a piping system either rises or falls to a set pressure.
• Liquid in the piping system acts against a PTFE diaphragm.
• The diaphragm works against a piston and spring, which triggers an electrical switch within the upper chamber of the unit.
• Spring pressure is set by simply threading the adjusting screw in and out.
• Series SWT contains a snap-action electric switch with three terminals.
• One is common, one is normally-open, and one is normally-closed.
• The normally-open switch will close upon reaching the set pressure, and the normally-closed switch will open when set pressure is reached.
• Set pressure can be reached by higher system pressure falling to the set value, or when lower system pressure rises to the set value.
• As an example, the switch can be set to actuate at 50 PSI, rising pressure (switch actuates when pressure rises to 50 PSI).
• When the pressure rises to 50 PSI the normally-open contact will close, and the normally-closed contact will open.
• Therefore, depending on how the switch is wired, a light, or a pump, etc. can be energized or de-energized…or one item could be energized and another de-energized at the same moment.
• As the pressure continues to rise, no further changes occur.

Technical specifications of PLAST-O-MATIC SWT

• Materials:  1/2″ NPT system inlet fitting.
• Wetted Parts: PVC type 1, grade 1, and PTFE There are no wetted elastomers
• Non-wetted Parts: PVC, type 1, grade 1, Ethylene Propylene Rubber (EPR), stainless steel, nylon, Buna-N.
• Pressure Rating: Maximum inlet pressure: 150 psi.
• Operating Pressure: There are three ranges, 15-50 PSI, 50-100 PSI, 100-150 PSI, each according to the spring that is installed. All three springs are included with the assembly. The middle range spring (50-100 PSI) is installed by the factory. The spring is changed by removing the Adjusting Screw. Do not disassemble the main housing. See “Setting the Switch” for further details.
• Electric Switch Rating: 16 amps @125 VAC, 1/2 HP, 16 amps @ 250 VAC, 1/2 HP. UL recognized and CSA approved. NOTE: A 25 Amp switch and a low deadband 3 Amp switch are available. See Section V, “Deadband”. Minimum order quantities may apply. Consult factory for additional details.
• Other: NEMA 4X construction; water and corrosion resistant.
• Operating Temp. Range: PVC: 40°F to 140°F