Presure-Seal Gate Valves 

Presure-seal gate valves standard material specifications

Note: Other materials are available upon request.

Presure-seal gate valves dimensions (mm) and weights (kg)

Manufacturing Process

STANDAR3DISATION
All products are manufactured in accordance with the guidelines of International Standard accepted all over the world such as Manufacturers Standardisation Society (MSS), American Petroleum Institute (API), American Society of Mechanical Engineers (ASME), British Standard (BS), Bureau of Indian Standard (BIS).

PROCURMENT OF RAW MATERIAL
In the manufacturing process we require Castings of different grades, Stainless steel Bars, forgings, hardware, gaskets & paints. All raw material purchase from the reputed & genuine concerned supplier.

QUALITY CONTROL
All raw materials are checked by our Quality Assurance Department prior to manufacturing process. For an example, when we received the castings, it is checked visually and dimensionally for machining tolerance. We also check the foundry chemical Test Certificate and physical test certificate, compared to suitable international standard and passed to machining shop for the further process, if it is rejected it is send back to the supplier.

MACHINING
The raw material issued to the machine shop for the machining, is machined strictly as per the relevant drawings.

INPROCESS TESTING
If it is found OK dimensionally the valve body and bonnet are sent for the hydro testing. All internal parts such as seat, disc, stem are measured by the Vernier Caliper or micrometer, if it is found O K than pass to assembly section for the further assembly. All the valve body and bonnet are tested on the motorized pump or hand pump as per the relevant standard. The theory being, when the body or the bonnet is under pressure there should not be any leakage or drops of the testing fluid from any portion of the castings. If any leakage observed, it is rejected and sent back to the foundries.

ASSEMBLY
The body and bonnet, which are Hydrostatically O K, are sent to assembly section, duly handled with care to avoid the scratches on the machined surfaces. In the assembly section body and bonnet are drilled on drill machine with the help of jigs & fixtures for uniformity and interchangeability.

LAPPING
In metal to metal seated valves, seat & disc/plug are lapped by Rough Lapping Paste to smoothen the seating surface and than lapped with very fine grade lapping paste for the proper sealing of disc & seat surface, to ensure zero leakage.

TESTING
After assembly of new complete valve is sent for Hydrostatic Testing. If no leakage is found as per the relevant standard, it is sent to finishing section.

FINISING/PAINTING & PACKING
The valve body and bonnet is debarred and finished by flexible shaft grinders for better appearance. One coat of corrosion resistance primer (red oxide) is sprayed, and colored as per the codes, twice for superior surface look.

Valves are packed either in wooden boxes or Gunny bags duly protected by ends enclosures and soft material to avoid any damages during transit.

Main Features :

• Body & Bonnet made from high quality casting with liberal sections. The castings are precision machined for high performance
• Bi-Directional Shut-Off
• Die moulded Graphite (Grafoil) Packing Rings, controlled clearance between stem, gland and bonnet bushing for guaranteed low emissions and also suitable for higher temperature.
• Deep stuffing box is providing for tightness and maximum long packing life.
• Swinging Eye Bolts facilitate easy access to the stuffing box.
• Back seating feature facilitates repacking of the stuffing box on line with the valve in fully open position.
• Seat Ring Screwed in to the body are replaceable type. Seal welded type Seat Ring & Integral Seat cab also be offered on special request.
• Stellited Disc, Seat Ring & Back Seat can also be offered on special request.
• Higher Pressure & Higher Size Valves are provided with Thrust Bearings and also with Gear drive arrangements.
• In built wear life for long duration of service.