• Dutco Tennant LLC, PO Box 233, Dubai, U.A.E.
Pilot Operated - Ductile Iron Plumbing Products

A compactly designed steam system produces clean dry steam in the boiler house that is ready for delivering high pressure through the distribution network. The potential for generating and supplying high-quality saturated steam at the lowest overall cost gets maximized by this. The needs are different at the point of use, however. Low steam can offer a wide range of advantages here as the design of the equipment and its construction can because of lower pressure rating cost less to buy, as the flash steam loss is reduced can cost less to operate, suffer fewer scaling problems due to lower steam temperature.

The pilot operated a reducing valve, works in a way such that it balances the downstream pressures against a control spring. A small valve plug over a seat (the pilot) gets modulated by this. In turn to the main valve diaphragm, where it modulates the main valve, the flow through this seat is directed. Under steady load conditions, the force set on the adjustment spring gets balanced by the pressure under the pilot diaphragm. The pilot valve thus gets sets and makes way for a constant flow across the main diaphragm. It is also ensured that the main valve is also settled to make way for stable downstream pressure. The pilot valve closes, and pressure is released from the main valve diaphragm through the control orifice, when the downstream pressure rises, to close the main valve. The pilot diaphragm immediately senses any variations in load or pressure which act to adjust the position of the main valve and ensures a constant downstream pressure. The use of an external pressure sensing pipe is recommended for achieving stable operating conditions, importantly when the valve is nearly used in its maximum capacity or under critical flow conditions.

The throttles position of the primary pilot-operated ductile iron valve gets controlled with the help of an adjustable pilot which operated with connection with an orifice. The downstream pressure is sensed by the pilot valve and this immediately reacts as the outlet pressure gets decreased or increased with the variations of the demand. The pilot can sense the pressure of the outlet and then immediately reacts to removing or adding from the top of the diaphragm of the main valve assembly which allows the valve to throttle and reposition as the pressure on the outlet tends for increasing or decreasing with the flow demand variations. The diaphragm of the pilot will sense the changes in the flow of the system automatically while it controls the primary valve constantly for opening, throttling or closing to maintain the preset, desired reduced pressure on the outlet. The required downstream pressure is offered by the throttling action of the main valve. The pilot-operated regulators are having the same important components of the direct-operated variants with the addition of a pilot that can separate the loading force of the diaphragm from the P2. This can help for controlling the force of the diaphragm with connections to the changes in P2.

Benefits -

  • Reduced installation costs as no external power source are required
  • Reduces total control investment - Pressure and temperature control valve combinations
  • Accurate control of pressure for constant process temperatures improves process efficiency and product quality
  • Reduces spares stocking costs due to interchangeability of many spares
  • Intrinsically safe as standard, for use in hazardous areas

From Dutco Tennant LLC get the most advanced range of Pilot Operated Pressure Reducing Valves for all your plumbing projects. We are the most trusted ductile iron valve supplier in the region with more than 40 years of experience.


  • Automatic Control Valve
  • Suitable for potable water applications
  • Pressure Adjusted by Integral Pilot Valve
  • Conforms to BS EN 558-1 Series 10
  • Flange Conforms to BS EN 1092 PN16
  • Available flanged PN25

Technical Data

Max Pressure 16 Bar
Working Temperature 0°C to +80°C