Diaphragm valve straight through - DIAVAL Fig. S | Comeval

Diaphragm Valve DIAVAL Fig. S Straight-Through

The Comeval DIAVAL Fig. S is a straight-through diaphragm valve designed for flow isolation in water networks, liquid processing, and abrasive media. Its seatless, bidirectional construction with a bolted bonnet and diaphragm sealing ensures the medium does not contact the operating mechanism. It is intended for on/off operation, not flow regulation.

Technical Specifications

• Body: EN-JS 1030 / GGG40 ductile iron or EN-JL 1040 / GG25 cast iron.
• Connections: Flanged DIN / ANSI, EN 1092-2 PN10/16 up to DN150 and PN10 for DN200–DN300, with optional ASA150 drilling.
• Sizes: Up to DN300.
• Pressure Limits: PS 10 bar for DN15–100, PS 6 bar for DN125–150, PS 3.5 bar for DN200–300, depending on body, lining, and diaphragm.
• Standards: EN 13397, EN 12516, EN 558 Series 1 / Series 7, EN 19, EN 12266-1 Rate A, PED 2014/68/EU, and Machinery Directive 2006/42/EC.

Diaphragm and Lining Selection

Selection is based on medium, temperature, corrosiveness, and presence of suspended solids. Available diaphragms include Natural Rubber, EPDM, Butyl, NBR, Neoprene, Hypalon, Viton, Linatex, and PTFE combinations. Body linings include hard/soft rubber, butyl, EPDM, neoprene, Hypalon, PFA, FEP, ETFE, Halar, and Linatex.

Applications

Suitable for:

• Water and wastewater treatment facilities,
• Slurry or abrasive liquids,
• Chemical processes with compatible materials,
• Isolation lines in auxiliary industrial networks.

The straight-through geometry reduces pressure drop compared to weir type valves and is preferred when free passage or reduced solid accumulation is required.

Handling and Maintenance

Basic operation with rising handwheel. Optional pneumatic or electric actuators, limit switches, sealed bonnet, padlocking, and interlocking are available. Maintenance focuses on leakage inspection, bonnet/body tightening, lining condition, and diaphragm replacement. The witness hole aids in diaphragm failure detection.