Bermad - Model 400 - Engineering Data

Closed Position:
Line Pressure applied to the control chamber of the valve creates a hydraulic force that moves the valve to the closed position and provides drip tight sealing.

Open Position:

Discharging the pressure from the control chamber to atmosphere or some other lower pressure zone, causes the line pressure acting on the plug to open the valve.

Modulating Closed:

The restriction continuously allows line pressure into the control chamber. The pilot controls outflow from the control chamber. Throttling when it senses a pressure rise, it causes pressure to accumulate in the control chamber, thereby forcing the valve to modulate closed.

Modulating Open:

The Pilot modulates open when it senses a pressure drop releasing more flow from the control chamber than the restriction can allow in. This causes the accumulated pressure in the control chamber to drop, and the valve modulates open.

Zero Slow Position:

When demand drops to zero, downstream pressure begins to rise as the flow enters a closed line. The pilot closes initiating a valve's irreversible closing process, eventually casing it to seal drip tight.

Fully Open Position:

When Upstream Pressure drops, the pilot blocks the pressure port and opens the drain port, venting the control chamber to the atmosphere. This fully open the valve, Minimizing Head loss.

Modulating Closed:

The pilot switches upon pressure rise, blocking the drain port and opening the pressure port. This pressurizes the control chamber, forcing the valve to modulate closed.

Locked Position:

When sensed pressure is equal to setting, the pilot shaft moves and blocks both the drain port and the pressure port. This locks the pressure in the control chamber, freezing the valve in its last position until condition change.

Zero Flow Position:

When Demand drops to zero, downstream pressure begins to rise as the flow enters a closed line. The pilot switches and pressurizes the control chamber initiating a valve's irreversible closing process, eventually causing it to seal drip tight.

[1] Fastening Bolts

Only four bolts (up to 10"; DN250 Valve) fasten valve cover to body, ensuring quick in-line inspection and service.

[2] Valve Cover

Locates, centralizes and fastens diaphragm and spring ensuring smooth and accurate performance. Simple construction enables quick in-line inspection and service.

[3] Auxiliary closing Spring.

One single spring fully meets valve requirements for operating pressure range, ensuring low opening pressure and secured closing.

[4] Diaphragm Assembly

One-piece elastomeric assembly that includes a peripherally supported flexible diaphragm, vulcanized with a rugged radial seal disk.

- No need for special Tyres of diaphragms to meet different operating conditions.

- Progressive dynamic guidance, resulting in exceptionally stable action and restrained closing.

- Valve opens and closes drip tight even with very low-pressure supply.

- Perfectly balanced diaphragm with no distortion caused by uneven hydraulic forces on shut off or during regulation.

- Exceptionally stable and chatter-free action during shut-off and pressure regulation.

[5] Body Threads

No need for nuts, simplifying valve disassembling and assembling for maintenance.

[6] Wide Body valve

Hydro-dynamically designed for efficient flow with minimal pressure loss and excellent resistance to cavitation.

[6.1] Diaphragm Supporting & Guiding

[6.2] Diaphragm Balancing Chamber

[6.3] Valve Seat: Full bore, valve port area clear of obstructions; no ribs or stem guides. Flow entrance is vertical to seal disk.

[6.4] End connections: Conforms to pressure ratings and standards of: ISO, ANSI, JIS, BS, and others.