Perfect repair of large size gate valve
The waste valves replaced from the working site are corroded by various media, fluid pressure, and affected by different temperatures. The parts including the valve body are affected by different degrees and different locations and cause valve malfunction. The drop cannot even be used. However, the used old valves that have been ineffective at the “validation” are not worthless and have no remediation value. They cannot be repaired and used, as long as they use the principles of metal structure, dynamics, fluidics, corrosion protection, welding, and heat treatment. Knowledge, the provision of essential maintenance equipment and the establishment of an experienced professional team, can fully implement deep-level, high-grade, high-quality repair and refurbishment of used valves.
API high pressure and high temperature power plant gate valve
The power plant valve usually should be high pressure and high temperature with medium water, steam, air. So material WCB, WC6, WC9 are widedly usded as main body material. The valve are designed with pressure seal bonnet for class 600 900, 1500, 2500 depends on size and working condition. The valve are usually with butt weld ends connection to avoid any leakage.Hard face sealing surface are often adopted.
Following are some pic of Power plant gate valves SGV offer.
Body inner side machining:
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API 600 Cast steel gate valve export to Russia
These lot valves are API 600 design and manufactured with special face to face standard. The face to face is 12mm longer than general 150lb API wedge gate valves ANSI B16.10( 6″ =267mm 8″=292mm) 6″ pieces are LCB body and 304 stem with 304 seat ring and stellite sealing face in disc. 4″ pieces are CF8M body and disc with hard seal sealing face.
Though we communicate with the client many times, the end user insist the face to face dimension was correct and suitable for local environment. It is special requirement for local, the dimension might be GOST standard and these valve will be used for instead former russia design valve. ASME B16.5 flanged connection for all valves.
Other 2 pieces valve are A216 wcb body material 300lb 20″ with double Stellite sealing face. The valve are inspected by third party as per API598. Include out surface, body test, seal test,and main dimension, out look, valve mark. Destination(Malaysia)
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SGV Wedge Gate Valve
SGV Wedge Gate Valve
Gate valve can only be fully open/close, and can not be used as adjusting valve.
In a wedge gate, the seats are not parallel, but taper inward from top to bottom. The discs are also tapered.The trim of wedge gate valve is wedge, which is vertical to medium flow direction. When the discs are forced into the seats, the wedging action provides the sealing force. That is effective for sealing, but one of the drawbacks of a wedge gate is the discs can get ‘stuck’ in the seat, especially if there is a great change in system temperature from when the valve is closed.
Wedge gate valve can be a unique type called inflexible disc; and can also be a flexible wedge.Gate valve under low pressure occasion, disc is forced to set to guarantee sealing; while disc is forced to contact another seat by high pressure condition. There is a slot structure inside the cavity to make sure the disc will not rotate under pressure, and also guarantee there is no friction before close position between seat and disc, thus reduces frictions on sealing face.
Design standards: API 600、GB/T 12234 and other
DN: 1/2 “-48”, DN15-DN1200
PN: Class150-Class1500
Body material: carbon steel, stainless steel, alloy etc.ASTM A216 WCB,A217 WC6,A351 CF8,A351 CF8M,A351 CF3,A351 CF3M,A351 CN7M
Operation: manual, gear, handwheel,hydraulic, motor etc.
OS&Y,Rising stem,Flexible Wedge Gate Valve,Solid Wedge Gate Valve
Bolted Bonnet,Threaded or welded seat ring, Renewable seat ring, Forged disc gate valve for small size,cast disc gate valve for big size
Wedge gate valve of Sangong has following advantages
1. Product fabrication is strictly according to API 600, full port design, on full open position, valve disc is higher that flow direction to guarantee flow smoothly, reduce pressure loss, high transmission efficiency.
2. For carbon material valve, seat is forged, high density, good sealing capacity. Sealing face use 13Cr or Stellite hard alloy material, overlay net thickness is over 2mm, valve seat is threaded or welded on the valve body, easy to maintain and dissemble.
3. Adopt rising stem, stem and disc is connected by a T shaped groove, T head and stem is forged together to guarantee enough connection strength. Flexible disc structure can avoid stuck caused by heat inflation
4. Back seal design will protect packing when valve is fully opened. Packing is flexible graphite, good sealing capacity, and also venting system is available. Packing bush and gland are ball structure, pressure process will enable the stem to automatically centralized, avoid stem stuck.
5. Bolted bonnet structure and thick hex nut fastening parts will ensure reliable function. Gasket adopt flexible graphite twist stainless steel or octagonal ring to get good sealing effect
6. Top entry nut design assures that, when the valve is open, even if demount the hand-wheel, stem and disc will not fall down. Stem is made by Aluminum bronze, and both sides set bearing, all this made the valve easy to operate.
API 600 Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries,ISO10434,BS1414 Gate valve
API 600 Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries
API Standard 600, Eleventh Edition , October 2001
ISO 10434 Gate Valves: 1998 ( BS1414 Gate Valves)
ANSI/API Std 600-2001
Contents Included
Introduction, Scope, Normative references, Definitions, Pressure/temperature ratings, Design, Body wall thickness,Bonnet wall thickness , Body dimensions, Flanged, Butt-welding ends, Body seats, Openings, Bonnet dimensions, Bonnet-to-body joint, Gate, Yoke, Stem and stem nut, Packing and packing box, Bolting, Operation, Auxiliary connections, Materials, Materials other than trim materials, Trim, Repair, Testing, inspection and examination, Pressure tests, Shell test, Closure tightness test , Backseat test, Optional closure tightness test, Inspection, At the valve manufacturer’s factory, Other than at the valve manufacturer’s factory, Extent of inspection, Examination, Supplementary examination, Marking, Legibility, Body markings, Ring joint markings, Identification plate marking, Preparation for despatch
Bolted bonnet steel gate valves for petroleum and natural gas industries
1 Scope
This International Standard specifies the requirements for a heavy duty series of bolted bonnet steel gate valves for petroleum refinery and related applications where corrosion, erosion and other service conditions indicate a need for full port openings, heavy wall sections and extra large stem diameters.
This specification sets forth the requirements for the following gate valve features:
— bolted bonnet;
— outside screw and yoke;
— rising stems;
— non-rising handwheels;
— single or double gate;
— wedge or parallel seating;
— metallic seating surfaces;
— flanged or butt-welding ends.
It covers valves of the nominal sizes DN:
25; 32; 40; 50; 65; 80; 100; 150; 200; 250; 300; 350; 400; 450; 500; 600
and is applicable for pressure designations PN:
20; 50; 110; 150; 260; 420
when metric sized bolt holes are provided in end flanges and PN designations are marked on the valve body.
It also covers valves of the corresponding nominal pipe sizes NPS:
1; 11/4; 11/2; 2; 21/2; 3; 4; 6; 8; 10; 12; 14; 16; 18; 20; 24
and applies for equivalent nominal Class ratings:
150; 300; 600; 900; 1500; 2500
when inch-sized bolt holes are provided in end flanges and Class designations are marked on the valve body.It also covers additional marking requirements for valves that are PN (or Class) designated but have flanges drilled for inch (or metric) bolt holes.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of the publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 7-1:1994,Pipe threads where pressure-tight joints are made on the threads—Part 1: Dimensions, tolerances and designation.
ISO 4200:1991,Plain end steel tubes, welded and seamless—Dimensions. ISO 5208:1993,Industrial valves—Pressure testing of valves. ISO 5209:1977,General purpose industrial valves—Marking.
ISO 5210:1991,Industrial valves—Multi-turn valve actuator attachments.
ISO 5752:—1),Metal valves for use in flanged pipe systems—Face-to-face and centre-to-face dimensions.
ISO 6708:1995,Pipework components — Definition and selection of DN (nominal size).
ISO 7005-1:1992,Metallic flanges — Part 1: Steel flanges.
ISO 7268:1983,Pipe components — Definition of nominal pressure.
ASME B1.1:1989,Unified inch screw threads (UN and UNR thread form).
ASME B1.5:1988 (R1994),Acme screw threads.
ASME B1.8:1988 (R1994),Stub Acme screw threads.
ASME B1.12:1987 (R1992),Screw threads — Class 5 interference — Fit thread.
ASME B1.20.1:1983 (R1992),Pipe threads, general purpose (inch).
ASME B16.5:1996,Pipe flanges and flanged fittings.
ASME B16.34:1996,Valves — Flanged, threaded and welding end.
ASME B18.2.2:1987 (R1993),Square and hex nuts (inch series).
ASTM A193:1996,Specification for alloy steel and stainless steel bolting materials for high-temperature service.
ASTM A194:1996,Specification for carbon and alloy steel nuts for bolts for high-pressure and high-temperature service.
ASTM A307:1994,Specification for carbon steel bolts and studs, 60 000 psi tensile strength.
MSS SP-55:1985 (R1990),Quality standard for steel castings, visual surface examination.
API Standard 600/ISO 10434:1998 American Petroleum Institute———————————
If you have any quesiton or enquiry about API600 gate valves, feel free contact Sangong team with info@sangongvalve.com. SGV also offer special API603 cast stainless steel gate valve.
About Gate Valve
The gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired. The gate faces can form a wedge shape or they can be parallel. Gate valves are primarily used to permit or prevent the flow of liquids, but typical gate valves shouldn’t be used for regulating flow, unless they are specifically designed for that purpose. Because of their ability to cut through liquids, gate valves are often used in the petroleum industry. Continue reading “About Gate Valve”