Penstock protection valve
| DESCRIPTION | MATERIAL USED |
|---|---|
| SIZE RANGE | Upto 4600 mm* |
| MAXIMUM WORKING PRESSURE | Upto 33 bar (g)* |
| TEMPERATURE RANGE | Upto 120 °C |
| DESIGN GOVERNING STANDARD & TESTING | IS 7326 / AWWA C504 / AWWA C516 / BS EN593 / Manufacturer's Standard |
| MODE OF OPERATION | Hydraulic for Penstock Protection (with counter weight) / Electrical for Penstock Isolation |
* Higher Sizes / Pressure available on request
Introduction
Penstock Protection Valve (PPV)
These specialized Butterfly valves are installed to protect hydro-electric installations against the possibility of penstock rupture.
These valves act as isolating devices for inspection of the penstock without dewatering the entire head race tunnel, failure of which can cause disastrous floods.
By virtue of their design and robust construction, these valves close down automatically and instantaneously in the event of downstream pipeline failure.
Features
In a typical Hydro Electric Power Station, the Penstock Protection Valve (PPV) is used to isolate the upstream pipe from the downstream side during penstock inspection and maintenance without having to de-water the entire dam.
If the penstock (on the downstream side of the valve) bursts, the entire head up to the burst point gets converted to velocity. The Penstock Protection Valve (PPV) closes automatically to prevent flooding on the downstream side.
In the event of load rejection at the power grid, the turbine runs at runaway speed. Under such conditions, the Penstock Protection Valve (PPV) closes to conserve water in the dam.
Design Specifications
| Parameter | Description | Details |
|---|---|---|
| Size Range | Upto 4600 mm* | |
| Maximum Working Pressure | Upto 33 bar (g)* | |
| Temperature Range | Upto 120 °C | |
| Material of Construction | Body | Carbon Steel (Cast / Fab) |
| Disc | Carbon Steel (Cast / Fab) | |
| Shaft | Stainless Steel | |
| Seal Type | Resilient Seal (EPDM / Nitrile / Viton) | |
| Seat Ring / Clamping Ring | Stainless Steel | |
| Bearing | Stainless Steel Backed PTFE | |
| Design Governing Standard & Testing | IS 7326 / AWWA C504 / AWWA C516 / BS EN 593 / Manufacturer’s Standard | |
| Seal Type | Single / Dual | |
| Mode of Operation | Hydraulic for Penstock Protection (with counter weight) / Electrical for Penstock Isolation | |
| No. of Drives | Single / Dual Cylinders | |
| Loading Condition | Balanced / Unbalanced | |
| Installation Arrangement | With Dismantling Joints / Downstream / Upstream Pipe Assembly | |
| Trip Mechanism | Available |