Text version of the page

KNIFE GATE VALVES -- MODEL A

DOC. A.12/07

DESIGN FEATURES IN DETAIL

1) BODY

Wafer style, one piece mono block cast body with guides to support the gate and seating wedges for tighter shut-off. For sizes bigger than DN1200 the construction of the body is fabricated in carbon steel with reinforcement ribs to withstand the maximum rated pressure. Full port designed to provide high flow rates with low pressure drops. The internal design of the valve avoids any build up of solids on the sealing area. The standard manufacturing materials are GG25 cast iron and CF8M stainless steel. Other materials like GGG50 nodular cast iron, A216WCB carbon steel and stainless steel alloys (AISI316Ti, Duplex, 254SMO, Uranus B6 ….) under request. Cast iron or steel valves are painted as standard with 80 microns anticorrosive protection of EPOXY (colour RAL 5015). Other anticorrosive protections available under request.

2) GATE

The standard manufacturing materials are AISI304 stainless steel for cast iron body valve and AISI316 stainless steel for CF8M stainless steel body valve. Other materials or combinations can be supplied under request. The gate is polished in both sides to provide a smooth contact surface with the sealing joint. At the same time the gate wedge is rounded to avoid cutting of the sealing. Several polishing grades, anti abrasion treatments and modifications are available to adapt the valve to the customer requirements.

3) SEAT

Six different seat constructions are available according to the application in which the knife gate valve will work as follows: Seat number 1: Metal to metal seat. This seat construction does not include any resilient sealing and the estimated leakage (considering water) is 1.5% of the flow. Seat number 2: Standard soft seated valve. This seat construction includes a resilient joint that is held on the valve body by an AISI316 stainless steel retaining ring. Seat number 3: Soft seated valve with reinforced socket. This seat construction includes a resilient joint that is held on the valve body by a reinforced socket with two functions (protect the valve body from abrasion and clean the gate when the valve is working with particles that stick on the gate). Seats number 4, 5 and 6: Equal to seats 1, 2 and 3 but including a deflector. The deflector is a conical shaped ring located on the valve inlet with two functions (protect the valve body from abrasion guide the flow to the centre of the valve). Note : Three materials are available for reinforced socket and deflector (CA-15 steel, CF8M and Ni-hard). C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / cmo@cmo.es http://www.cmo.es -3-