Plug Valves, End Connection : Flanged, Screwed

Plug Valves are the valves which have cylindrical or conical tapered “plugs” which can be rotated inside the valve body to control flow through the valve. The plugs have one or more hollow passageways going sideways through the plug. So, the fluid can flow through the plug when the valve is open, i.e. hollow passage way will coincide with inlet & outlet.
Plug Valves are simple and often economical. The 2-ports – 2-way plug valve is with two position at 90° open to allow the flow and close to stop the flow. It is possible to have more than
2-way like ball valves. In the 3-way valve, flow from one port could be directed to either second port or third port. A 3-way plug valve could also be designed to shift flow between ports 1 and
2, 2 and 3, or 1 and 3 and possibly even connected all 3-ports together. 3-way valve have L-port and T-Port. L-port will connect the middle port as 1 with 2 and rotating plug at 180° will connect port 1 with 3. Plug rotating at 90° will close the ports. T- port type valve will connect middle port as 1 with ports 2 & 3 and also will work like L-port.
Features:

• Full bore – pressure balanced – tapered – lubricated plug valve to satisfy the increasing demands of its customers for a plug valve with similar feature to those of a ball valve. Thus the full bore plug valves can be used in critical services such as slurries and mining or in pig gable gas pipelines.
• Unwanted deposits, that can be collected on the taper plug surface, will be cut off during the opening and closing of the valve, ensuring the fluid contact surfaces are kept clean and guaranteeing regular operation of the valve without risk of seizure.
• Applying a hard facing overlay of Stellite, Inconel 625 or tungsten carbide can enhance the metal to metal seat of the valve.
• The operating system of pressure balanced plug valves consists in the pressure equalization between the port area and the top/bottom of the plug, providing the plug with two holes. The upper hole connects the plug port area with the top of the plug, while the lower maintains the pressure equalization between the port area and the bottom of the plug. In this way the line pressure cannot lock the plug against the body taper, causing the valve to seize. Subsequently the Pressure Balance operating system permits a predictable torque even after a prolonged time in the open or closed position.
• Superior, longer lasting In-line Sealing.
• No Cavities, Reduce risk of Contamination.
• The tapered plug held firmly in to its tapered seat but can be so adjusted that complete leak tightness is achieved together with smooth valve operation.
• Plug Valves are available in Four Different Patterns – Viz. Full Bore – Short Pattern – Regular Pattern and Venturi Pattern.

Specifications:

• Lubricated pug valves are designed for most refining services according to API 599 or BS 5353 norms whichever is applicable for services to be used:
•  Specification for Wellhead and Christmas tree equipment – API 6A
•  Specification for pipe line valves – API 6D
•  Specification for Valve Fire Test – API 6FA
•  Recommended – practice for valve Fire test – API RP6F
•  Valve Inspection and Testing – API 598
•  Steel plug valve flanged or butt weld – API 599
• Aim to standardize the materials as well as instruction to manufacture valves suitable for
• energy transportation in the pipelines – API 6D norms:
•  Specification for Steel Casting for pressure purposes – BS 1504
•  Face to Face – Center to Face – End to End Steel Valves – BS 2080
•  Specification for steel Plug Valves – BS5353
•  Testing of Valves (Specification for Production Pressure Testing Requirements) –
• BS 6755 part 1
•  Testing of Valves (Spec. for Fire Testing Requirement) – BS 6755 part 2
•  Canadian Standard Association – CSA Z 245. 15
• ASME Standards:
•  Pipe Flanges and Flange Fittings – ASME/ANSI B16.5
•  Face to Face and End to End dimension of Valves – ASME / ANSI B16.10
•  Butt welding Ends – ASME/ANSI 16.25
•  Valves Flanged, Threaded and Welding ends – ASME /ANSI 16.34
•  Chemical pipe and Petroleum Refinery Piping – ASME/ANSI 31.3
•  Liquid Transportation System for Liquid Petroleum Gas – ASME/ANSI 31.4
•  Gas Transmission and Distribution Piping System – ASME /ANSI 31.8
•  Boiler and Pressure Vessel – ASME SECTION 8 DIV. 1 & 2
•  Boiler and Pressure Vessel – ASME SECTION V
•  Recommendation for Certification of Non-destructive Testing – ANST-TC-1A
• MSS Standards:
•  Standard Finish for Contact Face of Pipe Flanges – MSS - SP6
•  Standard Marking System for Valves – MSS - SP25
•  Steel Pipe Line Flanges – MSS - SP44
•  Quality Standard for Steel Casting – Magnetic Particle Examination – MSS- SP53
•  Quality Standard for Steel Casting – Radiographic Examination – MSS – SP54
•  Quality Standard for Steel Casting - Visual Method – MSS – SP55
•  Pressure Testing of Steel Valve – MSS - SP61
• Other:
•  National Association of Corrosion Engineers – NACE Standard MR01.75
•  American Society of Testing and Material – ASTM
• Sizes:
•  1/2” to 1-1/2” (DN15 to DN40) for ANSI 150 to 2500 (PN20 to PN 420) - RF Flange
•  1/2” to 2” (DN 15 to DN 50) for ANSI 150 to 2500 ( PN 20 to 420) –
• Female Screwed and Socket Weld Ends.
•  1/2” to 12” ( DN 15 to DN 300) - for ANSI 150 (PN 20) – For Short Pattern -
• RF & RTJ Flange and Butt Weld Type
•  6” to 12” ( DN 150 to DN 300) – for ANSI 150 (PN 20) - For Short Pattern -
• RF & RTJ Flange and Butt Weld Type
•  10” to 36” ( DN 250 to DN 900) for ANSI 150 PN 20) – For Venturi Pattern -
• RF & RTJ Flange and Butt Weld Type