GATE VALVES

EXPERT make Cast steel Gate Valves are tight sealing, Easy Operation isolation valves for liquid and gaseous fluids over a wide range of line pressures and temperatures.

Gate valves are of rising stem, outside screw and yoke (OS & Y) and with bolted bonnet construction. The rising stem indicates open or close position of the valve. The outside screw ensures easy lubrication and prevents corrosion and erosion by line fluids. The gate valves are used where minimum pressure drop and or bi­ directional on-off service are required.

Constructional Details

BODY AND BONNET

The body is designed for strength to meet the operating conditions and contoured to minimize erosion and resistance to flow. The bonnet is provided with renewable back seat arrangement.

FLEXIBLE WEDGE

The one piece flexible wedge minimizes stress concentration and assures tight sealing over a wide range of different operating temperature and pressure conditions. The flexible wedge shifts along the body of the valve during opening and closing, being held in position by a guide slot that minimizes the friction between body seat and wedge. This design is especially suited to compensate slight thermal deformations produced by the pipe or the valve itself safeguarding a better sealing between body and wedge seats.

BODY SEAT RINGS

The seat ring is seal welded to provide a bubble tight joint. On request the seat surface can be covered also with stellite, which provides increased resistance to wear, abrasion and erosion of the sealing surface.

PACKING

The standard packing is made of five or more pure graphite rings with square I rectangular section. The graphite is always treated with special corrosion inhibitors to prevent the corrosion of ferrite stainless steel stem due to galvanic cell action.

STEM

In all outside screw valves the stem is provided with integral backseat as emergency device in case of packing failure. To avoid any leakage the stem has a high finish degree and a strict diametrical clearance. In gate valves, the union of stem and wedge shall be in T form, designed to prevent the stem disengaging itself from the wedge while being in service.

GASKETS

The standard gasket is in pure graphite stainless steel reinforced. This type of gasket is suitable for many different applications.

BACK SEAT ARRANGEMENT

Back seats provide a seal between the stem and Bonnet & it is designed to relieve back pressure on the stem packing when fully seated.

GLAND ARRANGEMENT

The stuffing box holds adequate rings to enhance gland tightness and increases the life of packing rings.

ACCESSORIES

Valves can be supplied with special requirements like Extended Stem, Chain Wheel arrangement, Drain Plug, locking arrangement and By Pass arrangement.

Typical Applications Are

Water | Chemicals | Petrochemicals | Steam | Filtration System | Food & beverage | Oil & Gas Industries etc

Size Ranges

#150	DN 25 up to DN 400
#300	DN 25 up to DN 300
#600	DN 50 up to DN 200

Technical Data | Design Features

Design Standard	API600
Testing Standard	API598
Pressure/Temperature Rating	ASME B 16.34
Face to Face Dimensions	ASME B 16.10
End Connection	Flanged as per ASME B 16.5, Butt Weld as per ASME B16.25
Operation	Hand wheel, Gear, Electric actuator.
Material	ASTM A216 Gr.WCB / ASTM A351 Gr. CF8 / CF8M

On request valves can be supplied with special testing requirements like Helium Leak testing, NACE requirement, Radiography, Magnetic Particle test, IGC test.

Valves can also be offered with IBR certification.

Download Catalogue