DOrot model “CV” is an automatic control valve, activated by the pressure of the pipeline. The valve is in the “open” position when the upstream pressure is higher than the downstream pressure. Should the upstream pressure drop below of the downstream pressure, the valve will instantly close, preventing return flow. Opening and closing speeds are adjustable in order to prevent pressure surges caused, for example, by pump start-up and sudden valve closure.

The main valve is supplied in two models:

• Model 30, 30A for medium pressure (up to 16 bar / 230 psi)
• Model 31, 31A for high pressure (up to 25 bar / 350 psi).

The Dorot Series 300 Pump Control Valve (’30-BC) is an automatic controlled valve, activated by the pressure of the pipeline. The valve is assembled downstream of a pump and will open and close slowly when the solenoid is energized\de-energized respectively, thus preventing surges caused by sudden pump start-up or shut-off. The valve will close instantly on power failure.

Optional Pump Control valve applications:

• BC/PS Booster pump control & pressure sustaining - Pump control and Back-pressure sustaining valve.
• BC/DI  - Booster pump control & differential pressure sustaining - pump control, maintains constant flow at varying suction conditions. 
• BC/FR Booster pump control & flow-control
• BC/PR Booster pump control & pressure reducing
• BC/CD Booster pump control with extended, dynamic closure (for long pipelines)

Installed on the pump discharge.

Eliminating pressure surges caused by rapid change of the pipe velocity.

Opens slowly on the pump startup, and closes at adjustable pace before shut-off.

The pump motor is then switched-off by an electric interlink with the valve.

The valve eliminates damaging surges caused by pump start-up and shut-off. The electrically activated valve gradually opens on pump start up, and slowly closes before the pump is switched off. The valve will automatically close drip tight in case of power failure. Optional Additions: Flow Rate Limitation, Extended Closure, Two Stage Operating, Pressure Reducing and Pressure Sustaining.

• No slam operation
• Exceptionally low losses at high flow conditions
• Simple and reliable design
• Easy installation and maintenance

NS  Two-Stages, cushioned closure check valve

Developed to eliminate pressure slam of check valves, frequently found in roof-tank filling pumps of high-rise buildings. It opens on pump start, and closes at controlled pace when the pump stops.

The NS valve is located at the pump discharge (or on the common manifold of the pumps outlet), and is fullyopened through normal operation of the pump.

When the pump stops, and flow rate drops to nil, the valve starts closing. But unlike a standard hydraulic check valve that closes slowly from full- opening to fullclosure, the NS valve closes fast (within 2-4 seconds, depending on it`s size) to approximately 20% of its fullopening stroke (“Fast closure period”). By this time the returning flow is reduced to a negligible value.

Then, the closure pace of the NS valve is decreasing to a slower, adjustable speed (“Slow closure period”). This restricted movement of the valve trim generates a non-slam seating.

The described procedure does not require any electrical command and interlink between the valve and the pump as the device is activated automatically by the hydraulic parameters of the system.

The Dorot Series 300 Pressure-Sustaining (’30-PS’) activates by the pressure of the pipeline. The valve maintain a steady, predetermined pressure in the network, upstream of its location. Should the upstream pressure exceed the required set-point, the valve opens, increasing network flow, thus reducing its upstream pressure. If upstream pressure falls below the required value, the valve closes drip-tight.

• Better performance:

Regulates at a stable mode, regardless of valve-size, down to near-zero flow. Thus, eliminating the need for a special low flow plug-design (such as ‘V-port’) or a bypass valve.

‘Floating’, low-friction internal-trim design, guided by unique LPT® device.

• Increased reliability:

All control ports are fitted with SST sleeves for preventing corrosion-blockage

Pre-shaped reinforced diaphragm – for easier assembly and improved longevity.

• Reduced periodic inspection\maintenance labor:

The control-trim is fitted with a self-flushing, inline control-filter.

Easy in-situ adjustment and maintenance.

• Versatility:

• Accurate, stable control from no-flow to full flow 
• Simple and reliable design 
• Exceptionally low losses at high flow

The valve maintains upstream pressure, regardless of flow rate variations. The valve will be in the “closed” position if the upstream pressure drops below the set-point and will be “fully-opened” when the upstream pressure exceeds the set-point.

• Model 30, 30A for medium pressures (up to 16 bar / 230 psi)
• Model 31, 31A for high pressures (up to 25 bar / 350 psi).

Applications: For Virtual demand for VSD pumps