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KNIFE GATE VALVES A Series

KNIFE GATE VALVES A Series
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KNIFE GATE VALVES A Series

Product catalog summary
Product Description
Model A knife gate valves are wafer-style, uni-directional valves with a one-piece cast body. They feature guides for gate support and seating wedges, offering high flow rates with low pressure drops. Various seat and packing materials are available, and the face-to-face dimension adheres to CMO standards. An arrow on the body indicates the flow direction.
General Applications
These valves are suitable for liquids with up to 5% solids concentration and are used in industries such as pulp and paper, mining, effluent handling, chemical plants, food and beverage, bulk conveying, and sewage. For dry solids in gravity feed applications, installation with the arrow opposite to the flow direction is recommended.
Technical Data
Manufacturing sizes range from DN50 to DN1200, with working pressures varying by size. Standard flange connections are DIN PN10, with other standards available upon request. The valves comply with machinery, PED, and ATEX directives. All valves undergo hydrostatic testing, with body and seat test pressures exceeding maximum rated pressures.
Advantages
Model A valves have conically shaped inside body walls for easier closure and a guiding support system to handle back pressure without deformation. The stem is made of stainless steel 18/8, and the hand wheel is made of durable nodular iron GGG-50. The design allows for easy maintenance and actuator interchangeability.
Design Features
  • Body: Made from GG25 cast iron or CF8M stainless steel, designed to prevent solids buildup.
  • Gate: Polished stainless steel, with options for different materials and treatments.
  • Seat: Six seat constructions available, including metal-to-metal and soft-seated options.
  • Packing: Standard packing includes an EPDM o-ring, with options for different materials.
  • Spindle: Made of stainless steel 18/8, available in rising or non-rising stem designs.
  • Actuators: Various actuators can be supplied, with easy interchangeability.
Accessories
Available accessories include mirror polished gates, PTFE lined gates, stellited gates, scrapers, air injection in packing glands, heating jackets, flushing holes, mechanical limit switches, solenoid valves, and more.
Knife Gate Valves - Model A Overview

General Dimensions:
1. Chainwheel – Rising Stem: Available in both rising and non-rising stem configurations.
2. Pneumatic Double Acting: Operates with an air supply pressure of 6 kg/cm2. The standard design supports pressures between 6 and 10 kg/cm2, with 10 kg/cm2 being the maximum. For valves DN50 to DN200, components are made from aluminum and AISI304, while larger valves use nodular cast iron or carbon steel.
3. Pneumatic Single Acting: Features spring to close or open options. Suitable for valves up to DN300, with larger sizes requiring a double acting actuator with an air tank.
4. Electric Actuator: Available for both rising and non-rising stem configurations.
5. Hydraulic Actuator: Operates with an oil supply pressure of 135 kg/cm2.

Materials and Construction:
- Double Acting Actuator: Aluminum, AISI304, steel with nitrile coating, and nitrile o-rings.
- Single Acting Actuator: Aluminum, cast iron or carbon steel, AISI304, steel with nitrile coating, nitrile o-rings, and steel springs.

Additional Information:
For more detailed specifications, refer to the "CMO pneumatic actuators" catalogue.
See more

Catalog excerpts

KNIFE GATE VALVES A Series -1

Wafer style, uni-directional knife gate valve. One piece integral cast body with guides to support the gate and seating wedges. High flow rates with low pressure drops. Several seat and packing materials available. Face to face dimension according CMO standard. Arrow in the body pointing the flow direction. > This knife gate valve is appropriate for liquids with a solids concentration of maximum 5%. If it is used for dry solids in gravity feed applications it is recommended to be installed with the arrow in the opposite direction to the flow direction. Designed for a wide range of applications such us: - Pulp and Paper. - Mining. - Effluent handling plants. - Chemical plants. - Food and beverage. - Bulk conveying. - Sewage applications. - Chemical plants. > Standard manufacturing sizes: From DN50 up to DN1200 (bigger sizes under request) Working pressures: From DN 50 to DN 125: 10 (kg/cm2) DN 150: 8 (kg/cm2) DN 200: 7 (kg/cm2) From DN 250 to DN 300: 5 (kg/cm2) From DN 350 to DN 400: 4 (kg/cm2) From DN 450 to DN 600: 3 (kg/cm2) From DN 700 to DN 1200: 2 (kg/cm2) Note : These pressures are to be applied on the valve following the direction of the arrow stamped on the body side. Due to the valve design with supporting guides it is allowed 30% of these pressures in the opposite direction of the arrow. Flange connection drillings: The standard flange connection is according to DIN PN10. Other flange connections such as, ANSI 150, DIN PN6 PN16 ֖ PN25, British Standard, Australian Standard, JIS Standard, are available under request. Applied Directives: Directive 98/37/CE (machinery), Directive 97/23/CE (PED: Group 2), Directive 94/9/CE (ATEX: Group II, Cat. 3 / Zones 2 and 22) Quality Dossier: All valves are hydrostatically tested at CMO with water and CMO material and test certificates can be provided. Body test pressure = Maximum rated pressure x 1,5 Seat test pressure = Maximum rated pressure x 1,1 C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / [email protected] http://www.cmo.es -1- >

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KNIFE GATE VALVES A Series -2

When a knife gate valve stays open for a long time and its inside body walls are parallel a big torque is needed to close it. The model A has conically shaped inside body walls that provide a bigger space. So, when closing the knife the product stocked in the inside of the body is cleared easily. This valve is defined as unidirectional and on unidirectional knife gate valves when there is a back pressure the knife can bend. This is something that can not happen with the CMO valve because it has a guiding supports system that allows to the valve to work with a back pressure of 30% of the maximum...

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KNIFE GATE VALVES A Series -3

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...

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KNIFE GATE VALVES A Series -4

DOC. A.12/07 Resilient Seat Materials EPDM This is the standard resilient seat installed on CMO valves. It can be used in many applications, but generally it is used for water and products diluited in water at temperatures not higher than 90C.The EPDM rubber can also be used for abrasive products. It provides 100% tightness. NITRILE It is used for greasy fluids or oils at temperatures not higher than 90 ںC. It provides 100% tightness. VITON Appropriate for corrosive products and high temperatures up to 190C in continuous and picks of 210ںC. It provides 100% tightness. SYLICONE The silicone is...

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KNIFE GATE VALVES A Series -5

DOC. A.12/07 P.T.F.E. LUBRICATED It is made of PTFE filament threads which are impregnated using vaccum with a dispersion of PTFE and a special lubricant which helps the work at high speed. It is braided by the diagonal system. Suitable for valves and pumps working with nearly all the fluids, specially the more corrosives, including concentrated oils and oxidants. It is also suitable for fluids with solid contents. P(bar) = 100/ T = -200+270 C PH = 0-14 GRAPHITE FILAMENT It is made of graphite threads of high purity. It is braided by the diagonal system and impregnated with a small quantity of...

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KNIFE GATE VALVES A Series -6

Several types of accessories are available to adapt the valve to specific working conditions, such as: Mirror Polished Gate The mirror polished gate is specially recommended for food industry and applications were the solids can stick on the gate. The mirror polished gate is an alternative to solve such kind issues. PTFE Lined Gate As the mirror polished gate, it improves the performance of the valve against the adherence. Stellited gate Addition of stellite material on the gate wedge to protect it from abrasion. Scraper in the packing It cleans the gate during the opening movement to avoid the...

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KNIFE GATE VALVES A Series -7

The following actuators are available: C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / [email protected] http://www.cmo.es -7- >

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KNIFE GATE VALVES A Series -8

C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / [email protected] http://www.cmo.es -8- >

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KNIFE GATE VALVES A Series -9

C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / [email protected] http://www.cmo.es -9- >

 Open the catalog to page 9
KNIFE GATE VALVES A Series -10

C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / [email protected] http://www.cmo.es -10- >

 Open the catalog to page 10
KNIFE GATE VALVES A Series -11

C.M.O. Amategui Aldea 142, 20400 Txarama-Tolosa (SPAIN) Phone: 943-67.33.99 / Fax:943.67.24.40 / [email protected] http://www.cmo.es -11- >

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KNIFE GATE VALVES A Series -12

As standard the CMO double acting and single acting actuators are designed to work between 6 and 10 Kg/cm2 air supply pressure. 10 Kg/cm2 is the maximum allowed air supply pressure. When the air supply pressure is less than 6 Kg/cm2 the actuator is oversized. Double acting actuator: For valves of diameter DN50 up to DN200 the cylinder jacket and the caps are in aluminium, the piston rod in AISI304, the cylinder piston in steel covered by nitrile and the o-rings in nitrile. For valves bigger than DN200 the caps are manufactured in nodular cast iron or carbon steel. The actuator can be manufactured...

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.