BS 1212-2:1990

What is BS 1212-2 – Diaphragm type float operated valves about?  

The float valve is a simple mechanical liquid level controller that detects changes of elevation in the liquid free surface and opens or closes a valve accordingly.  

BS 1212 a set of British Standards that discusses float operated valves. The main aim of the BS 1212 series is to provide manufacturers with best industry specifications to ensure their float operated valves contribute to the enhanced performance of water supply systems. 

BS 1212-2 is the second part of the series that specifies materials, dimensions, tolerances and performance requirements for diaphragm type float operated valves (copper alloy body) of nominal sizes) and " with seat numbers 3, 5, 6 and 9 intended for use with floats complying with BS 1968 and BS 2456.  

Who is BS 1212-2 - Diaphragm type float operated valves for?   

BS 1212-2 on diaphragm type float operated valves is relevant to:  

• Manufacturers of diaphragm type float operated valves  
• Anyone involved in operating, designing, maintenance and commissioning of components used in water supply systems 
• Engineers 
• Quality control and testing personnel 
• Local bodies 

Why should you use BS 1212-2 - Diaphragm type float operated valves?   

Float control systems require both float switches and float valves to demonstrate adequate quality and performance levels. For this reason, it is necessary that the components comply with best industry specifications, such that the operational efficiency of water supply systems be maintained. 

In this regard, BS 1212-2 walks you through specifications for diaphragm type float operated valves.  

BS 1212-2 provides you with guidance on appropriate designation, marking, and material requirements as per components. Guidance on design, construction and dimensions are also provided.  

Method of test for shut-off when assembled with appropriate float, for backflow prevention, for effect of hydraulic pressure on discharge arrangement is also covered. 

Float operated valves complying with BS 1212-2 and carrying the Kitemark are automatically eligible for listing in the Water Research Centre Fittings Scheme Directory of Water Fittings. 

As a result, BS 1212-2 can help you manufacture high-quality diaphragm type float operated valves such that they are fit for purpose, and contribute to the credibility of your business. 

What has changed since the last update? 

BS 1212-2:1990 supersedes BS 1212-2:1970, which is withdrawn. The new features in BS 1212-2:1990 include the following: 

• The possible production of certain components from plastics materials 
• A seat numbering system 
• A bottom entry inlet connection and its associated inlet elbow, with adjustable stay
• A recognition of the greater lifting effort of plastics floats over copper floats of equivalent size
• A test for plastics backnut strength, in line with BS 1212-3
• A recognition of current manufacturing practice by deletion of reference to the use of agate tipped seats 
• A recognition of methods of attachment of the discharge arrangements currently used in float valves manufactured in accordance with BS 1212-3, and a test to verify their effectiveness 
• A modification of the method of dimensioning some components to ensure the lever does not rise above the horizontal at valve closure; 
• The dimensional alignment of the body inlet connection with BS 1212-1, which now requires only one seat joint ring for either plastics or metal seats