- 2081 Bhadra · 5 marks
Short note: Sluice valve
Short answer
A sluice (gate) valve opens or closes flow completely by moving a wedge gate across the pipe with a screw spindle. It offers low head loss when fully open, tight shut-off, but is unsuitable for throttling and is commonly used for isolation on mains.
Write a short note on the sluice valve with sketch.
A sluice valve (gate valve or cutoff valve) is the most common valve on water mains. It is used to fully open or fully shut off the flow, and is placed at junctions, at branches and at intervals along the line to isolate a section for repair.
hand wheel
|
spindle (screw)
_|_
| |
======| | |====== gate (wedge) moves
|___| across the pipe
body
Construction
- A cast-iron body and bonnet, bronze seat rings and a wedge-shaped gate (disc), moved by a screw-threaded spindle and operated by a hand wheel or key.
- The spindle may be rising (the stem rises as the valve opens, which shows its position) or non-rising (used for underground valves, operated with a key through a valve box).
- The end connections are usually flanged.
Working
Turning the wheel clockwise lowers the gate across the flow, closing the valve; turning it anticlockwise lifts the gate fully clear of the waterway, opening the valve with little loss of head.
Features
- Advantages: low head loss when fully open (the flow path is straight), tight shut-off, flow in either direction, simple and durable.
- Disadvantages: unsuitable for throttling (the gate vibrates and the seats erode), slow to operate (many turns of the wheel, although this helps against water hammer), and bulky and costly in large sizes.
✓ Answer checked by Claude Opus 5.5 (high effort)