Bidirectional Designs
Compare QU and QJ series using the individual model documentation.
ALFACOM ENGINEERING LTD.
Knife Gate Valves
Isolation valves for suitable applications involving sludge, suspended solids, fibrous media or process slurries. Select the sealing arrangement, materials and operation to match the actual process.
Knife Gate Valves · ALFACOM catalogue
THE PRODUCT RANGE
Explore the Range
Explore the equipment and selection topics below, then review the detailed catalogue for the selected product.
English product details and the corresponding technical PDFs are provided below.
Unidirectional Designs
Review QB series where a defined sealing direction is required.
Materials & Operation
Match the blade, body and sealing materials to the process and specify the required method of operation.
Explore Catalogue Models
Read the English model details below. Product images are illustrative; confirm the exact configuration, dimensions and operating limits in the model documentation. Availability and lead time are confirmed on enquiry.
QJ bidirectional knife gate valve
QU / QUZ73X bidirectional knife gate valve
QB / QBZ73X unidirectional knife gate valve
QJ Bidirectional Rubber-Lined Knife Gate Valves
QJ valves provide bidirectional isolation with rubber lining in the flow passage and a full-port design. The groove-free bottom arrangement is intended to reduce retained material in the body cavity.
Consider the series for compatible slurry, sludge and suspended-solids duties. Select the lining, seat and blade materials for chemical compatibility, abrasion and temperature. The catalogue includes several operating options; confirm the required manual, geared or actuated configuration.
Pressure capability varies by size. Provide the line size, medium and solids content, operating pressure and temperature, flange standard, lining requirements and operation. Confirm the selected model's pressure limit independently of the flange drilling.
QU / QUZ73X Bidirectional Knife Gate Valves
The QU series uses bidirectional sealing, a full-port passage and a U-shaped resilient seat at the bottom of the body. The groove-free arrangement is intended to reduce material accumulation around the seat.
The catalogue illustrates ductile-iron construction with a stainless steel gate and model-specific sealing and operating arrangements. Confirm all materials and configuration for the ordered valve.
Select by medium, solids characteristics, operating differential pressure, temperature, nominal size and installation. The permitted working pressure changes with valve size; the flange designation alone does not establish the valve's allowable pressure.
QB / QBZ73X Unidirectional Knife Gate Valves
QB knife gate valves use unidirectional sealing and a replaceable resilient seat retained by a metal ring. Seat replacement is an identified maintenance feature of the documented design.
Specify the required operating configuration and compatible body, blade and seat materials. Follow the direction and mounting instructions for the selected valve; unidirectional sealing must be considered in the installation.
Provide the size, medium, solids content, pressure, temperature, flange standard and operating method. Check size-specific pressure data in the technical manual before ordering. Actuator and feedback requirements are selected for the complete assembly.
APPLICATION BEFORE SPECIFICATION
Selection Starts with Your Application
Specify the medium and solids, pressure and temperature, size, flow direction, body and sealing materials, connections and required operation. Unidirectional and bidirectional designs have different installation and sealing requirements; confirm them against the model documentation.
Catalogue & Technical Documents
Review the model-specific technical information and installation requirements. Send a specification, drawing or existing model reference if you need help selecting equipment.
Discuss Your Application
Send your requirements or a photo of the existing equipment for technical assistance and a quotation.
Availability and lead time are confirmed for the requested model and quantity.