BS 4151:1967 PDF

What is BS 4151 - Pneumatic valve positioners about?

BS 4151 is a British standard that specifies tests designed to determine the performance of pneumatic valve positioners which accept input signals of 3 lbf/in2 to 15 lbf/in2. Although some valve positioners may be tested without being fitted to a valve operator, there are some positioners that form an integral part of the operator and these cannot be separately tested. The method of evaluation described in BS 4151 , therefore, specifies the use of a valve operator in all cases since this allows a ready comparison to be made between different types. The operator may be a spring-opposed or double-acting diaphragm or piston. Note: Throughout BS 4151 the term “valve operator” is u...