API 600 Gate Valve

INTRODUCTION (Bolted bonnet Gate valves):

VHV Bolted bonnet Gate valves serve as ON-OFF application valves just as a standard gate valve serves as a bidirectional valve which assists flow in either direction. With the help of wedging action, it serves as an effective seal against the flow. The valve, during its full open condition, forms a through conduit without any obstruction. This helps with smooth flow and less pressure drop. VHV Gate valves are heavy duty, outside screw and yoke type, bolted bonnet, rising stem, and non-rising handwheel type. The straight through bore design assures minimum turbulence, erosion and resistance to flow. These valves are handwheel operated or gear operated depending upon the size.

STANDARD FEATURES(Bolted bonnet Gate valves):

VHV Gate valves are heavy duty, outside screw and yoke type, Bolted bonnet, rising stem handwheel type.

Gate Valve design complies to API 600, API 603, ASME B 16.34, BS 1414

The straight through bore design assures minimum turbulence, erosion, and resistance to flow.

Valves are handwheel operated and gear operated depending upon the size.

Cast body precisely machined with integral flanges and Cast bonnet with integral yoke up to 10”.

One-piece flexible wedge is standard. Solid wedge shall be provided on request.

Rising stem with precision ACME thread with single or double start for quick operation.

Stem packing is designed for optimum control of fugitive emission leakage to the atmosphere and is assured by the polished finish stem sealing area.

Fugitive Emissions – Complies to API 624 and ISO 15848-1 (<50 ppm / Class AH leakage levels, optional).

Live loading on packing can be provided as request.

Back seat shall be either threaded or welded in to facilitate the replacement of packing under line pressure.

Seat rings are welded in or integral to provide bubble tight joint.

Two piece gland and gland flange arrangement for reduced stem wear.

By-Pass, Lantern rings, special connection are as optional.

Nace service either MR-01-75 or MR-01-03 as required.

Valves can be supplied with Pneumatic, Hydraulic, or electric actuators and accessories like limit switch, etc can be provided as optional.

Body gasket leakage <100 ppm observed on eight sizes tested as per API 624 Annexure A.

Fire Safe – By design and tested to API 607 / ISO 10497.

CE Marking – Meets requirements of Pressure Equipment Directive 2014/68/EU, Annexure III, Module H.

Robust stem-wedge design connection successfully tested as per API RP 591 Annex B.

Hard-faced body guides and wedge slots (sizes >24”).

Inconel overlay/ cladded options offered.

TECHNICAL DATA(Bolted bonnet Gate valves):

INTRODUCTION(Pressure Seal Bonnet Gate valves):

VHV Pressure Seal Gate Valves are intended for high pressure and high temperature applications for all types of fluids, except where severe coking may occur. Because of their design and materials of construction, pressure seal valves are an excellent choice for nuclear steam generating stations, industrial/chemical plants, and thermal power plants. Pressure Seal Gate Valves offer efficiency in flow passage and sealing, weight saving, ease of installation and simplicity in maintenance. The basic concept of pressure seal valves is that the initial bonnet pull up bolts tighten the bonnet, which in turn seals the pressure seal gasket to the body. Then the system pressure assist provides more force to seal the gasket. Hence, as system pressure increases, the potential for leakage through the body/bonnet joint decreases.

TECHNICAL DATA(Pressure Seal Bonnet Gate valves):

 STANDARD FEATURES(Pressure Seal Bonnet Gate valves):

Pressure-Seal mechanism utilizes line pressure to enhance seal; ensures sealing integrity at higher operating pressures.

Gate Valve design complies to API 600, ASME B 16.34, MSS SP144.

Valves are handwheel operated and gear operated depending upon the size.

Cast body precisely machined with integral flanges.

One-piece flexible wedge is standard. Solid wedge shall be provided on request.

Rising stem with precision ACME thread with single or double start for quick operation.

Stem packing is designed for optimum control of fugitive emission leakage to the atmosphere and is assured by the polished finish stem sealing area.

Fugitive Emissions – Complies to API 624 and ISO 15848-1.

Live loading on packing can be provided as request.

Live loading of bonnet bolts for F91/ C12A valves.

Back seat shall be either threaded or welded in to facilitate the replacement of packing under line pressure.

Seat rings are welded in or integral to provide bubble tight joint.

Two piece gland and gland flange arrangement for reduced stem wear.

By-pass arrangement provided for over-pressure protection based on customer requirement.

Nace service either MR-01-75 or MR-01-03 as required.

Valves can be supplied with Hydraulic, electric actuators and accessories like limit switch, etc can be provided as optional.

Robust stem-wedge design connection successfully tested as per API RP 591 Annex B.

Applications of API 600 wedge gate valves:

This kind of API 600 Wedge Gate valve provide optimum performance in conditions where high flow efficiency, tight shut off and long service is required. A wide choice of shell and trim materials do cover the whole range of applications, from the every-day type of non-corrosive service to critical service with highly aggressive media. it is widely utilized in pipeline with liquid & other fluids,Petrol,oil,Chemical,Petrochemical,Power and Utilities etc

INTRODUCTION(Parallel slide gate valves):

Parallel slide gate valves are widely used in high pressure and high temperature services such as steam and feedwater.Double discs in parallel postion with compressed spring between them,double sealing with line pressure makes better sealing performance.

Designed standard ASME B16.34,API600, BS1414

Size Range：2″~72″(DN50~DN1800）
Pressure Class：ASME CLASS 150LBS~4500LBS
Main material：carbon steel, low temperature steel, staniless steel, alloy steel & duplex steel etc.
Ends：RF, BW, RTJ etc.
Operation type：H.O,G.O,Pneumatic operation,Actuator operation etc.

Various type of operation for parallel slide gate valves:hand wheel,manual gear,electric actuator etc.

What is the parallel slide gate valve?

Parallel Slide Gate Valve is a special design of gate valve.

It’s an alternative to the traditional flexible wedge type gate valves. The disc is in two halves, compressed spring Inconel X750 loaded, that seat on parallel seat rings. The disc “slides” in contact with the seats, hence the name.

The discs are in permanent contact with the seat rings, getting a tight seal due to the horizontal inconel spring located in between and without the wedging system help.

Sealing mechanism of the parallel slide gate valves.

When the pipe pressure or pressure difference of two sides is small,the compressed spring will push the discs to the sealing rings,it’s the initial sealing of the parallel slide gate valves under low pressure conditions.

When the pipeline pressure increase,the increasing line pressure will push the disc against the seat ring with force in the low pressure side,which creates the secondary seal. The higher the medium pressure,the better the sealing performance

Therefore this valve type is widely used in high pressure and high temperature services such as steam and feedwater.

The advantages of the parallel slide gate valve versus the traditional wedge type product are:

The discs of parallel slide gate valve will never block in closed position,while it may occur with a wedge type that has been closed with the line in temperature and opened when the line is cold.

The opening/closing torque of parallel slide gate valve is much lower than a corresponding gate valve wedge type valve,resulting in smaller actuator and less expensive actuation systems.

The “sliding” feature keeps dirt away from the sealing surfaces.

Main Design features of Parallel slide gate valves:

Two discs and just one wedge design gate valve.

Parallel slide gate valve provides a smooth flow path between seats.

This design of gate valve is commonly used for clean fluids and steam applications.

System pressure is used to provide isolation. The closing is only made over one of the seats. The higher pressure in the system, the better closing tightness.

The discs have a certain movement to assure its right alignment with the seats contact faces when closing (seal is established on outlet seat face only), avoiding any mechanical stress.

The inconel spring located between both discs, provides initial seating force. Once the discs are in the right position, no additional torque is necessary to achieve a positive seal.

Torque requirement is lower than other gate valves as wedge type because needs lower operative forces.

The wiping action of the discs over seats while the valve is operating removes debris and prevents premature wear of the components. A long life service is guaranteed by means of hardening seats and discs with an extra hard material as Stellite 6, Tribaloy or others.

Parallel slide system avoids jamming related to cooling down of the pipeline.

A wide range of construction materials, actuation systems and accessories are available for each case.

Application of Parallel Slide Gate Valve:

Parallel Slide Gate Valve is widely used in the field chemical,petroleum, natural gas,oil and natural gas production wellhead device, conveying and storage pipelines (Class150~2500/PN1.0~42.0MPa, operating temperature -29~450℃),pipes with suspended particle media,urban gas pipeline,water engineering.it’s designed to provide isolation and transmission of flow in a piping system or a component when closed, sometimes can be installed in the pump outlet for regulating or control of flow.