1/2" True Union Diaphragm Valve (SK-TUDV-005)

The 1/2" PVC True Union Diaphragm Valve (SK-TUDV-005) is a precision flow control valve built for chemical dosing, water treatment, and process piping applications where clean, reliable throttling and shut-off are required at the 1/2" service size. At this size, diaphragm valves are most commonly found on chemical injection points, reagent feed lines, small-diameter dosing loops, and laboratory or institutional fluid systems where precise flow regulation and complete isolation of valve internals from the process fluid are non-negotiable.

Like all weir-type diaphragm valves, the SK-TUDV-005 controls flow by pressing a flexible EPDM diaphragm against an internal weir in the valve body — completely separating the actuating mechanism from the fluid passing through. There are no ball cavities, no gate recesses, and no metal surfaces contacting the process fluid. This makes the diaphragm valve the correct choice for corrosive chemical service, viscous fluids, and liquids with suspended solids that would trap in, corrode, or abrade the internals of a conventional ball or gate valve. When closed, the diaphragm seats cleanly on the weir for a crevice-free shut-off that leaves no fluid trapped in the valve body — critical in chemical dosing applications where residual fluid in the valve creates dosing inaccuracies or cross-contamination risk.

The true union end design is what makes this valve a practical choice for any system that requires periodic maintenance. The socket union ends solvent cement permanently into the pipeline — the valve body unthreads from the unions for complete in-line removal without cutting pipe, disconnecting fittings, or disturbing adjacent components. Diaphragm replacement, cleaning, and inspection are all performed with the unions remaining in the pipe, minimizing maintenance time and system downtime on chemical dosing and treatment systems where valve service intervals are routine.

The gray PVC body is manufactured to ASTM D1784 Cell Class 12454 for broad resistance to acids, bases, salts, and oxidizing chemicals at service temperatures up to 140°F. The clear PVC bonnet provides a direct visual of process fluid color and clarity through the top of the valve, while the rising position indicator gives a precise read on diaphragm stroke position — essential in throttling applications where the valve is operated at a partial-open setting to regulate flow rate rather than simply opened or closed. The large multi-turn handwheel allows smooth, stepless control over diaphragm travel — a level of flow regulation precision that a quarter-turn ball valve fundamentally cannot deliver.

Rated at 150 PSI at 70°F non-shock, the SK-TUDV-005 handles the pressure demands of most chemical dosing, water treatment, and light industrial process applications comfortably. The valve body features two mounting screw holes in the base for panel, bracket, or manifold mounting in chemical feed skids, dosing systems, or compact equipment configurations.

Key Features:

• Weir-type diaphragm design for clean shut-off with no trapped fluid or internal pockets
• EPDM diaphragm fully isolates valve internals from process fluid — zero metal-to-fluid contact
• True union socket ends for complete in-line valve removal and servicing without cutting pipe
• Socket (slip) connections for solvent cement installation into Schedule 40 or 80 PVC systems
• Gray PVC body — ASTM D1784, Cell Class 12454 — broad acid, base, and chemical resistance
• Clear PVC bonnet for direct visual monitoring of process fluid and position status
• Multi-turn handwheel for precise, stepless throttling control
• Rising position indicator shows exact diaphragm stroke at all times
• 150 PSI rated at 70°F; 140°F maximum service temperature
• Mounting provisions — two screw holes in valve body base
• Can be installed in any orientation — horizontal, vertical, or angled

Specifications:

Industries & Applications:

• Chemical Dosing & Injection Systems — The 1/2" size is the most common specification for chemical dosing points on water treatment systems, cooling towers, and process loops; the diaphragm design isolates valve internals from hypochlorite, acid, caustic, and other aggressive dosing chemicals that would degrade metal or standard thermoplastic valves
• Water Treatment & Purification — Used on chemical feed lines for chlorination, pH adjustment, coagulant dosing, and antiscalant injection in municipal, commercial, and industrial water treatment systems; the weir design handles concentrated treatment chemicals cleanly without corrosion or residual contamination
• Pool & Spa Chemical Feed — Specified on chemical injection lines handling liquid chlorine, muriatic acid, and algaecide in automated pool chemical systems where precise, repeatable dosing and corrosion resistance are both required
• Laboratory & Institutional Plumbing — Used on reagent supply lines, lab drain systems, and process water circuits in university, medical, and research facilities where chemical compatibility, precise flow control, and clean shut-off are specified requirements
• Pharmaceutical & Food Processing — The crevice-free weir shut-off and EPDM diaphragm construction make this valve appropriate for sanitary-adjacent process lines where fluid entrapment or metal contamination cannot be tolerated
• Greenhouse & Fertigation Systems — Installed on fertilizer concentrate injection points and chemical feed loops in commercial greenhouse and hydroponic operations where acid and nutrient solution compatibility and accurate flow throttling are both required
• Industrial Process Piping — Throttling and isolation on small-diameter process lines handling acids, bases, solvents, and reactive chemicals in manufacturing, finishing, and chemical processing environments where metal valves would corrode or contaminate the process
• Aquaculture & Specialty Water Systems — Used on chemical treatment and pH adjustment feed lines in recirculating aquaculture systems, public aquariums, and specialty water management applications where chemically inert valve materials and clean shut-off are critical