Technical Requirements and Standardization of Plug Valves
This specification establishes strict engineering standards for the design, selection of structural materials, determination of dimensional parameters, and regulates pressure and temperature performance for metal-seated plug valves. The document defines quality control protocols, acceptance testing procedures, and inspection checks to ensure the reliability of the valves supplied by EV Group China.
- Steel, nickel, and specialized alloys: valves with flanged or butt-weld connections in the size range of 15 ≤ DN ≤ 600 (1/2 ≤ NPS ≤ 24), as well as ductile iron plug valves with flanges.
- Small-bore valves: components with threaded or socket-weld connections for sizes 15 ≤ DN ≤ 50 (1/2 ≤ NPS ≤ 2). Body elements complying with ASME B16.34 allow for combined connection types: flange/weld or thread/socket.
- Execution types: the standard covers full-bore valves with two-way coaxial ports, both with and without lubrication systems. Note: three-way and four-way plug valve configurations are not included in this specification.
- Tandem systems: the technical requirements apply to dual valves equipped with two independent operating plugs integrated into a common body.
The specification from EV Group China regulates requirements for valves with internal bodies, plugs, and port linings, as well as hard facings on functional elements. The selection of specific lining materials remains at the discretion of the designer and is not detailed in this standard.
For plug valves complying with ASME B16.34 (classes 150–2500), additional reliability requirements are provided. Ductile iron products (classes 150 and 300) undergo mandatory verification for compliance with ASME B16.42 regarding P-T ratings, wall thickness, and flange connection geometry.
Classification of Plug Valve Design Groups
The valves considered in the standard are divided into four structural types, each with specific face-to-face installation dimensions:
- Short Pattern: applicable for classes 150 and 300. Flanged plug valves correspond to the installation dimensions of steel gate valves in the range of 40 ≤ DN ≤ 300 (1 1/2 ≤ NPS ≤ 12).
- Regular Pattern: a design with an increased port area compared to the Venturi type.
- Venturi Pattern: minimizes pressure loss due to optimized body and plug geometry, ensuring smooth flow of the medium.
- Full Port: a design with a circular channel cross-section, the dimensions of which strictly comply with Appendix A of the ASME B16.34 standard.
The standard applies to valves with the following nominal sizes:
- NPS (inches): 1/2, 3/4, 1, 1 1/4, 1 1/2, 2, 2 1/2, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 24.
- DN (metric): 15, 20, 25, 32, 40, 50, 65, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, 600.
Technical data required for placing an order with EV Group China are detailed in Appendix A to this standard.