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Stainless Steel Cycle Stop Valve Constant Pressure System with ZS18 Stainless Steel Pressure Tank

The Cycle Stop Valve Constant Pressure System is an effective way to have steady water pressure, reduced pump cycling, and a reduced pressure tank size all without using a variable frequency drive (VFD) constant pressure system.

The CSV1A Stainless Steel Cycle Stop Valve can automatically adjust pump output to match variable flow requirements. It is a pressure adjustable valve, and can handle from 1-25 GPM.

All Stainless Steel Components:

1 1/4" MPT x 1 1/4" Barb

Check Valve (1 1/4" FPT)

Cycle Stop Valve #CSV1A

(2) Plugs (1/2")

Zilmet ZS18 4.8 Gallon Stainless Steel Pressure Tank

Coupling (1 1/4" FPT)

1" / 1-1/4" Manifold

Plug (1")

Hose Bib (3/4" MPT)

Pressure Gauge - Back Mount (1/4" MPT)

Bushing (3/4" MPT x 1/4" FPT)

Nipple (1/4" x 3" MPT)

Pressure Relief Valve, preset at 100 PSI (3/4" MPT)

Shutoff Valve (1 1/4" FPT)

Square-D Pressure Switch, choose from 20/40, 30/50, 40/60, 50/70 or 60/80 PSI at checkout (additional $4.00 charge for 30/50 Low cut-off & 40/60 Low cut-off, and $46.00 charge for 50/70 & 60/80). 

Mounting Bracket and Hardware

Teflon Tape for Stainless Steel included

Product Features


  • Constant water pressure
  • Reduce pump cycling to extend pump life
  • Small pressure tank
  • Easier maintenance than VFD system

The maximum flow rate and maximum Well water pressure tanks depends on the pump's performance

Pressure setting:

  • Cycle Stop Valve pressure should be between cut-in and cut-off of pressure switch
  • Cycle Stop Valve pressure should be at least 10 psi below cut-off pressure
  • It is suggested to have the Cycle Stop Valve pressure 5 psi higher than cut-in pressure
  • The air pressure for the pressure tank should be 5 psi below the cut-in pressure


For example, here are the ideal settings for a 55 psi constant pressure system:

Cycle Stop Valve pressure: 55 psi

Pressure Switch: cut-in 50 psi / cut-off 70 psi

Pressure Tank: 45 psi (AIR)

How it works:

Faucet on, Water pressure drop from 70 psi to 50 psi, Pump starts, Water pressure would keep at 55 psi, Faucet off, Water pressure raise to 70 psi, Pump stop

Please Note:  The installation package comes unassembled.

 The Cycle Stop Valve model CSV1A is a pump control valve that automatically adjust pump output to match variable flow requirements. Downstream of the CSV1A pressure remains constant as long as demand is between the upper and lower limits of the valve. The 1" CSV1A handle from 1-25 GPM.


304 Stainless Steel

Molded Thermoplastic Spring Cage

EPDM with dacron cloth insert diaphragm

Replaceable acetal cartridge

Pressure - Temperature

Max Temperature:          180 F

Max shut off head:          400 psi

Adjustable pressure:       15-150 psi

Max differential pressure: 125 psi


1-25 GPM flow range

Variable flow with reduced pressure

Tank fill rate 1 GPM

All internal parts corrosion resistant and included in a drop in cartridge

Dual Threaded: 1" female NPT thread & 1 1/4" male NPT thread

[2] 1/2" & [1] 3/4" additional ports

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