Features

- Stainless steel construction suitable for submergence or splashing by sewage and sludge;

- Maintenance free integral seat design, within 316 Grade stainless steel body. Other components of the design manufactured in the same grade material include gate, superstructure and all fasteners;

- The valve body is tapped to suit the flange drilling up stream as required. Design suitable for end of line isolation.

- There is no gland sealing on this valve so it is a maintenance free piece of equipment;

- The valve stem is driven through a fixed bronze drive bush operated by a 316 grade stainless steel tube fitted with a standard square drive. This unique design fully isolates the threaded drive spindle from sewage contamination when it is in the open position, as it is totally contained within a permanently lubricated and protected enclosure;

- Operating stem extensions can be easily fitted to the valve’s non rising square drive and can be manufactured in various materials to suit requirements. It is recommended that extensions are supported independently when over three metres in length.

Ordering Details
Size (specify in millimetres)
Valveco Knife Gate Valve
(Size), D,AMS,M,X,NRA.

Less expensive valves manufactured with cast iron bodies have proven to fail in this application and do not shut off the inlet flow after a number of years in the open position. The reason for cast iron valve failures is that unlike wedge gate valves, popular for this application pre 15 - 20 years ago, the gate to body clearance in all knife gate valve designs is very small. This small clearance results in the valve jamming in the open position due to corrosion build up under the gland area, accelerated by any gland leakage which may occur. Stainless steel (Grade 316) body valves do not have this problem; Fully isolated threaded drive stem with permanent lubrication, resists jamming. Enclosed bonnet type knife gate valves have failures due to the threaded drive being constantly immersed in the sewage and sludge as it fills up the body of the valve. Valves protected with stem enclosure do not have this problem; Although metal to metal seats have a slight downstream leakage when closed, the benefit of not having to
maintain a resilient seat ring prone to damage are far outweighed by this minor inconvenience. Metal to metal seats do not have problems; Tapered square drive allows for extension stem fitting by slip over drive attachment. This design is far superior to “fixed to valve stem” extension which transfer misalignment to the valve superstructure and
can cause failures. Removable square drives do not have this problem. Valveco Industries have been supplying Knife Gate Valves for over 20 years, this design valve reflects the requirements of council and authorities in the need for a valve that functions when required and needs virtually no maintenance.