Knife Gate Valves Type B
The AKO type B knife gate valve is a bi-directional wafer valve for media of high consistency.
It is predominantly used in the
- paper and pulp
- and chemical industries,
- in water treatment,
- energy generation and
- power station technology
The nominal widths available for the knife gate valves range from DN50 to DN600 with flange connections complying with EN 1092 PN10 or alternatively, ANSI B16.5 (class 150).
Back to Knife Gate Valves Overview.
Actuators of Knife Gate Valve type B
Drive variants include a manually actuated handwheel model with rising or non-rising stem or double-acting pneumatic cylinders and electric actuators.
Design features of Knife Gate Valve type B
The structure of the bi-directional Knife Gate Valves encompasses a two-part wafer style body screwed together, with reinforced ribs for larger nominal diameters for extra body strength.
The two-part wafer style body is available in grey cast iron (GG25) or alternatively in stainless steel AISI 1.4408 (CF8M). The stainless steel body is also fitted with internal sliding strips made out of UHMW polyethylene to improve closing and opening characteristics.
The slide plate is manufactured using stainless steel AISI 304 or AISI 316 as standard.
The slide plate is a single part with a circular opening. When closing, a slice of the product flow is cut off. The slide plate is ground smooth on both sides to prevent jamming and/or preserve seals and gland packing.
On request the thickness of the Knife Gate Valves plate can be increased for higher operating pressures and/or higher quality material can be used.
The two-part, screwed together body and slide plate seat is sealed tight by an elastomer seal in a stainless steel retainer ring; however, this can also be achieved without the elastomer seal (sealed with metal).
The standard material used for the Knife Gate Valves elastomer seal is EPDM. Alternatively, nitrile, viton, PTFE or silicone (FDA certification) are available.
The gland packing consists of several layers of braided fibre on each side. An EPDM o-ring is additionally integrated into the layers gland packing as standard. In addition to greased cotton, a PTFE-coated synthetic fibre, braided PTFE, graphite, ceramic fibre or Dynapack can be used as gland packing for the knife gate valves.
Maximal operating pressures for AKO Knife Gate Valve type B
DN50-DN250: 10 bar
DN300-DN400: 6 bar
DN450: 5 bar
DN500-DN600: 4 bar