BS 5163-2 is a technical specification that specifies isolating valves and hydrants installed in underground pipelines primarily carrying water intended for human consumption within the United Kingdom are required to be fitted with a stem cap to enable them to be operated by a ring-key and bar or T-shaped key.
The stem cap is fitted to the top of the valve stem to convert the manufacturer’s stem configuration to mate with operating keys. Two sizes of stem cap are specified, covering respectively, valves from DN 50 through DN 300 and DN 350 through DN 600.
Note: Stem caps are also commonly used on other waterworks apparatus, e.g. penstocks.
BS 5163-2 on stem caps for use on isolating valves is useful for:
BS 5163-2 states the terms and definitions, design requirements, and preparation for storage and transport. The flow and temperature of water in pipelines and plumbing fixtures are controlled by water valves. The valves control steady flow and volume when correctly placed and operated.
Isolation valves are essential components of a water distribution system because they allow water companies to do maintenance without shutting down substantial portions of the system. Isolation valves separate the actuation mechanism of a valve from the media being moved. Using BS 5163-2 guidelines provides manufacturers with high-quality superior product specifications for global acceptance. BS 5163-2 ensures safety, protection, and quality management for its users.