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Pilot-Operated, Normally-Closed PTFE Bellows Seal Solenoid Valves Series PS

Series PS is a proven design for aggressive chemicals


  • 1,000,000+ cycle bubble-tight design; over 2,000,000 cycles has been achieved in field use.
  • No metal parts in wetted area.
  • Rugged thermoplastic construction.
  • Patented Fail-Dry vented design.
  • Resistant to atmospheric corrosion.
  • Uses line pressure to assist operation, which allows extremely high Cv performance, as well as outstanding pressure ratings.
  • Molded corrosion-resistant coil assembly.
  • 11 watt/Nema 4X CSA approved water and dust tight enclosure.
  • All valves are individually inspected and 100% tested.
  • Optional coil connector light indicates when valve is energized.

     Film Click here for brief video of how Series PS works.

Mode of Operation:

Requires 5 psi greater pressure at inlet to function properly. With proper differential, Series PS is normally closed (energize to open). Inlet pressure can be as high as 140 psi; backpressure (outlet) can be as high as 70 psi — as long as the outlet pressure is 5 psi lower through the entire operating range.

When the signal is sent to close the valve, it takes about a second for the pilot pressure to overcome the process pressure. Once the pressure is overcome, closure is instantaneous, and potential for water hammer must be considered prior to specification.


Designed for pressure service; suitable for drain applications as long as 5 psi differential is maintained. Not designed for vacuum service. Not suitable for liquids containing particulate unless a .007 filter is used. Not suitable for liquids which tend to precipitate solids.


Series PS automatically shuts off flow of highly corrosive and ultra-pure liquids. They can handle acids, caustics, solvents, chlorine solutions, sodium solutions, deionized water, reverse osmosis water, brewery processes, etc. as long as a 5 psi differential is maintained. Series PS is not suitable for solutions containing particulate matter or solutions that tend to precipitate solids. Care should be taken when processing liquids prone to crystallization, such as salt solutions, etc. The internal workings of the PS valve can be adversely affected by crystallization. If you have any questions, please contact our technical group at (973) 256-3000.


Valves are normally closed by inlet pressure on a diaphragm over the main orifice. When the valve is energized and the pilot orifice is opened, the pressure above the primary diaphragm is released downstream. Once this pressure is released, the pressure below the main diaphragm forces it to open. When the valve is de-energized, pressure is returned to the top of the diaphragm, forcing it to close. The action of the pilot and diaphragm result in a slight delay in the opening and closing, generally a second or two. (Note that without the 5 psi required differential, the pressure above the primary diaphragm will not be released, and the valve will not function properly).

Available in 1/2″, 3/4″, 1″, 1-1/2″, 2″ & 3″ NPT sizes. Not all materials available in 2″ or 3″ sizes: 2″ PS available in PVC, PP & PVDF. 3″ PS available in PVC only. If your size and material needs differ, please contact factory.

After 1,000,000 cycles, we recommend that the valve be disassembled and inspected. It is also recommended to replace the elastomer seals at this point. Contact your distributor for a seal kit. For heavy use applications, you may wish to order a spare seal kit with the valve. Seal replacement takes but a few minutes with common tools; no special training is required.


dimensional drawing of the PVC pilot solenoid valve.

dimensions of the True Blue pilot solenoid valve.
mounting hole information for the True Blue pilot solenoid valve.


Coil Specifications

Certifications: NEMA 4X, CSA approved
Insulation Class: F
Coil Surface Temperature: 185 F (85 C)
Max. Allowable Ambient Temperature: 104 F (40 C)
VA Inrush: 66
VA Holding: 24
Connector Type: DIN connector is standard
AC Voltages: 24/60, 120/60, 240/60, 230/50
DC Voltages: 24 VDC, 12 VDC (12 VDC has certain limitations. Please consult factory)
Most coils CSA certified.

Pressure & Liquid Specifications

Maximum Inlet**: 140 PSI/9.7 Bar @ 75F/24C
Maximum Inlet: 40 PSI/2.8 Bar @ 140F/60C
Minimum Inlet: 5 PSI/0.4 Bar
Maximum Outlet: 70 PSI/4.8 Bar @ 75F/24C
Minimum Differential: 5 PSI/0.4 Bar
**This rating is for PVC. Consult factory for other materials.

Note about Particulate: Liquid media should be filtered with 80 mesh (.007) filter or finer. 

Flow Capacity vs. Pipe Size

Pipe Size…..Cv

Questions? Please call our Technical Group at (973) 256-3000

Ordering Information:

ordering information and part numbers for the True Blue pilot solenoid valve.

NOTE: Optional body and seal materials are available, depending on specifications, lead time, and quantity. 2″ PS available in PVC, PP & PVDF. 3″ PS available in PVC only.

Cost Comparison

When comparing valves, it is important to consider both the operating life, and how easily/costly it is to service the valve. Below is a lifetime cost comparison chart, pitting the Plast-O-Matic True Blue® Series PS against a well known competitive brand…

Plast-O-Matic True Blue Solenoid Valves  beat the competitor's valve in life cycle cost comparison

  • The valves compared are 1″ NPT pilot-operated solenoid valves, with PVC bodies and FKM seals. (FKM is often compared to the brand name Viton, which is a registered trademark of DuPont Dow Elastomers) Prices are per catalog, January 2001, and are subject to change.
  • The Plast-O-Matic valve has a 9.5 Cv rating with a rated pressure range of 5 – 140 psi.
  • The competition’s valve has a 10.3 Cv rating with a rated pressure range of 7 – 85 psi.
  • Plast-O-Matic recommends inspection at 1,000,000 cycles. Assuming a rebuild kit is required — and it may not be — the valve can be returned to like-new condition in a few minutes, without any special training. Cost of the rebuild kit is $155.
  • The competitor states: “The valve will last 200,000 to 500,000 cycles, at which point we recommend buying a new valve, because the rebuild kit is virtually the entire valve and costs approximately the same.”
  • Even when competitive valves are priced hundreds of dollars lower, Plast-O-Matic users still come out way ahead in terms of cost per cycle. For example, if the initial cost of the other valve were $174, the total life cycle cost in this comparison would still be $166 more than Plast-O-Matic…not to mention the staggering cost of multiple downtimes.

Helpful Links:

PDF Catalog File for the product shown on this page (Series PS)

Determining Amperage for a Plast-O-Matic Solenoid Valve This is a technical document in Microsoft Word format that explains how to calculate the amperage required for Plast-O-Matic AC or DC coils.

Series PS Homepage