Straight Through Diaphragm Valves, 3/4-16 Inch, CL125/150 LB

Product Name: Straight Through Diaphragm Valves
Design Standard: BS 5156, MSS SP-88
Body Material: Cast Iron, ASTM A216 WCB, A351 CF8, CF8M
Lining & Diaphragm Material: Natural Rubber, EPDM, Hard Rubber
Size: 3/4-16 Inch (DN20-DN400)
Pressure: PN10, PN16, Class 125 LB, Class 150 LB
Operation: Handwheel, Pneumatic, Electric
Temperature Range: -29°C to 80°C

The straight through diaphragm valve features a design where the diaphragm lifts completely when opened, enabling unobstructed, bi-directional flow. Upon closure, the diaphragm seals tightly against the flow path, ensuring complete shutoff, even in pipelines containing abrasive media like gravel or fibrous materials. Compared to weir-type diaphragm valves, this design requires diaphragms with greater elasticity, which limits the range of suitable elastic materials for diaphragm construction.

1. Corrosion Resistance

Our diaphragm valves are ideal for applications requiring superior corrosion resistance. A wide selection of linings and diaphragm materials, ranging from elastomers to fluoropolymers, offers an economical alternative to exotic alloys. These material options ensure optimal compatibility with corrosive media, making KOSEN valves the preferred choice in aggressive service environments.

2. Abrasion Resistance

Engineered with advanced polymer technology, KOSEN diaphragm valves deliver exceptional abrasion resistance. The straight through configuration handles up to 100% solids and maintains reliable shutoff performance with soft rubber diaphragms. All designs conform to MSS SP-88 and BS EN 12266-1 standards, ensuring durability and sealing integrity even under highly abrasive conditions.

3. Leak Tight Performance

Our diaphragm valves provide 100% leak-tight sealing under both pressure and vacuum conditions, even after thousands of cycles. This performance meets or exceeds MSS SP-88 and BS EN 12266-1 standards. The valves’ design eliminates fugitive emissions, minimizing product loss and reducing handling and environmental compliance costs.

4. Isolated Operating Mechanism

All working parts are completely isolated from the process media, protecting the operating mechanism from corrosion and wear. Positive shutoff is ensured even in applications with frequent cycling or suspended particulates—unlike other valve types where internal exposure can compromise function over time.

5. Easy Maintenance

The three-part valve design allows for quick and easy maintenance or actuator retrofitting without removing the valve body from the pipeline. This modular structure reduces downtime, lowers maintenance costs, and extends the service life of the valve, delivering a lower total cost of ownership.

6. Control Capability

Our straight through diaphragm valves also offer excellent throttling and flow control capabilities. A cavity-free, streamlined flow path enhances control precision, making these valves well-suited for applications requiring both on/off and modulating control.

Standards Compliance and Design Features

» Size: 3/4-16 Inch (DN20-DN400)
» Pressure Rating: ANSI Class 125 LB, Class 150 LB, PN6, PN10, PN16
» All Standards: MSS SP-88, BS 5156, ASME B16.34, DIN 3202, ASME B16.1, BS EN 558, ASME B16.5 CL150, EN 1092, EN 12226, ISO 5208, API 598, BS 4504 or equivalents
» Materials: Cast Iron, Ductile Iron, Carbon Steel, Stainless Steel, or Other Specials
» Optional Lining: Natural Rubber, Butyl, EDPM, Hard Rubber and etc.
» Ends Connections: Flanged RF or FF, Screwed
» Optional Locking Device Position indicator
» Optional Direct Mounting to ISO 5211
» Regular Bore
» Handwheel, Electric or Pneumatic operated

Structural Diagram

Main Material