Standards Development

Scope

This British Standard specifies pressure/temperature ratings, dimensions, some aspects of design, materials, performance requirements, testing (both type and production testing), marking and preparation for storage and transportation of double regulating globe valves and flow measurement devices used for heating and chilled water systems.

This standard covers double regulating globe valves and flow measurement devices in the form of fixed and variable orifice valves and as individual orifice fittings made from steel, cast iron and copper alloys with flanged, threaded and compres

NOTE 1 The information to be supplied by the purchaser at the time of enquiry and/or order is given in Appendix A.

NOTE 2 This standard does not cover methods of installation.

NOTE 3 The titles of the publications referred to in this standard are listed on pages 18 and 19.”

Purpose

This standard was published in 1990 and amended once in 1991. The product specified is still very much in current use and is relevant to a large section of the heating and ventilation product market for valves used in commercial buildings. However, there are important aspects of the standard which need updating and therefore a full revision is proposed.

The main reasons the standards requires a full revision are as follows:

• To align the standard with current practice and EN standards:

• To align the standard with the Pressure Equipment Directive and the Pressure Equipment (Safety) Regulations 2016;

• To update its references to current and relevant standards;

• To provide clarification.

Additionally, the revision is proposed to cover the following subjects:

• Clause 1: Scope – Re-write (see proposed revision of scope below*);

• Clause 5: Ranges of nominal pressure – Consideration to be given to increasing PN rating coverage;

• Clause 7.4: Pressure tapping point – Review of this clause and consideration to be given to removing Table 5 and relationship to dimension. Review of actual test data showing how performance to tolerance is achieved;

• Clause 8.4: Pressure tapping points - Review of this clause and consideration to be given to clarifying the definition, including a diagram and having more freedom over design ideas on variable orifice products.

*The scope is proposed to be revised as follows:

“This document specifies the requirement for metallic double regulating globe valves and flow measurement devices having flanged, wafer, threaded or compression end connections.

This document specifies the requirements for design and functional characteristics including materials, pressure/temperature ratings, dimensions, testing, hydraulic performance and marking.

This document applies to metallic double regulating globe valves and flow measurement devices in the form of fixed and variable orifice valves and as individual orifice fittings used for heating and chilled water systems.

The range of nominal sizes covered is:

a) Flanged: DN10. DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, DN100, DN125, DN150, DN200, DN250, DN300.

b) Threaded: 3/8, ½, ¾, 1, 1.1/4, 1.1/2, 2. c) Compression: 15mm, 22mm 28mm. The range of pressure designations is covered by: d) Flanged: PN10, PN16, PN20, PN25, PN40

e) Threaded: PN10, PN16, PN20, PN25, PN32, PN40

f) Compression: PN16*

Note: * refer to BS EN 1254-2 for pressure rating against pipe size.”