1-1/2 " True Union Diaphragm Valve (SK-TUDV-015)

The 1-1/2" PVC True Union Diaphragm Valve (SK-TUDV-015) is a weir-type, multi-turn isolation and throttling valve built for chemical dosing headers, water treatment plant distribution piping, pool and spa chemical feed systems, and industrial process lines at the 1-1/2" commercial mainline service size where complete fluid isolation from all valve internals, precise throttling control, and in-line serviceability are the specification requirements that drive valve selection. At the 1-1/2" size, the true union diaphragm valve steps decisively into commercial and industrial mainline territory — this is not a branch connection valve but a primary isolation and flow control valve on chemical distribution headers, water treatment plant chemical feed mains, commercial pool recirculation chemical injection points, industrial process chemical transfer lines, and regulated facility piping systems where the flow volume, system consequence of valve failure, and maintenance access requirements at the mainline size all reinforce the specification case for diaphragm valve construction over ball valves, gate valves, and other valve types at this critical service diameter.

The weir-type diaphragm design is the defining feature that separates this valve from every other valve type at any service size, and at the 1-1/2" commercial mainline size its operational advantages are at their most consequential. The EPDM diaphragm seals against a contoured weir body to open and close the flow path — with no metal components, no stem packing, no seats, and no mechanical sealing surfaces ever in contact with the process fluid. On a 1-1/2" chemical distribution header or water treatment chemical feed main where the valve handles acids, caustics, oxidizing agents, chlorine solutions, or other aggressive process chemicals at meaningful flow volumes, this complete separation between the valve's mechanical operating components and the process fluid is both a safety and a reliability specification requirement. Metal contamination of sensitive process streams is eliminated. Chemical attack on valve internals is eliminated. The corrosion, scale buildup, and chemical degradation that progressively compromise metal valve performance in aggressive chemical service — and that require valve replacement at unpredictable intervals — are eliminated by design rather than by material selection. The EPDM diaphragm provides broad compatibility across the acids, bases, chlorine solutions, oxidizing agents, and industrial process chemicals most commonly encountered in water treatment, pool chemical feed, and industrial process piping service at this size.

The gray PVC body provides the chemical resistance, structural integrity, and Schedule 80-equivalent wall construction appropriate for a 1-1/2" commercial chemical service valve, while the clear bonnet serves a functional purpose beyond aesthetics — the transparent bonnet allows the diaphragm and the valve's internal condition to be visually inspected without disassembly, and the rising stem position indicator provides a continuous, unambiguous visual read on valve position from any angle in the mechanical room, equipment room, or process area where the valve is installed. On a 1-1/2" chemical header with multiple valves in close proximity, this visual position confirmation eliminates the ambiguity that quarter-turn levers and handwheels on non-indicating valves create in high-consequence process environments. The multi-turn handwheel allows precise, gradual flow adjustment — throttling the 1-1/2" flow path from fully closed through any intermediate position to fully open with complete operator control at every point in the stroke, eliminating the water hammer and system shock that quarter-turn valves produce when rapidly actuated on 1-1/2" mainline flow systems.

The true union socket end design is the maintenance specification that makes this valve the correct long-term installation for any 1-1/2" system requiring in-line valve access. The socket union connectors solvent cement permanently into the 1-1/2" PVC pipeline — the valve carrier body unthreads cleanly from both unions for complete in-line removal without cutting pipe, draining the system beyond the immediate valve location, or disturbing adjacent piping and equipment. On a 1-1/2" chemical dosing header or water treatment chemical feed main where multiple valves are installed in close proximity and diaphragm replacement is a scheduled maintenance event, true union serviceability means each valve's diaphragm, bonnet, and stem components can be replaced in-line with the unions staying permanently cemented in the line — a maintenance efficiency that is operationally and economically significant at the 1-1/2" commercial mainline size where valve repair and replacement costs, system downtime, and chemical exposure during maintenance are all proportionally greater than at smaller branch sizes.

Rated at 150 PSI at 70°F with a 140°F maximum service temperature, the SK-TUDV-015 handles the pressure and temperature conditions of commercial chemical service piping within standard PVC service limits. Pressure derated above 70°F per PVC temperature-pressure curves.

Key Features:

• Weir-type diaphragm design — complete fluid isolation from all valve operating components
• Gray PVC body with clear bonnet for visual diaphragm inspection without disassembly
• EPDM diaphragm for broad chemical compatibility across acids, bases, chlorine, and oxidizers
• True union socket ends for in-line valve removal without cutting pipe
• Multi-turn handwheel for precise, gradual throttling and water-hammer-free actuation
• Rising stem position indicator — continuous visual valve position confirmation
• 150 PSI rated at 70°F; 140°F maximum service temperature
• No metal-to-fluid contact — eliminates metal contamination and chemical attack on internals
• Fully field-serviceable — diaphragm, bonnet, and stem replaceable in-line
• Handles slurries, viscous fluids, and aggressive chemical service unsuitable for ball or gate valves

Specifications:

Industries & Applications:

• Chemical Dosing & Distribution Headers — The 1-1/2" size is the primary isolation and flow control valve on commercial and industrial chemical dosing distribution headers where multiple injection points are supplied from a single main; the weir-type diaphragm eliminates metal-to-fluid contact on chlorine solutions, sodium hypochlorite, sulfuric acid, caustic soda, and other aggressive dosing chemicals that corrode and contaminate metal valve internals; multi-turn throttling allows precise flow adjustment across all downstream injection points without water hammer on the main, and true union serviceability allows individual valve diaphragm replacement without isolating the entire header
• Water Treatment Plant — Chemical Feed Mains — Installed on 1-1/2" chemical feed primary distribution mains, coagulant and flocculant supply headers, pH adjustment chemical feed connections, and chlorination system primary distribution lines in municipal and industrial water treatment plants where complete fluid isolation, chemical resistance to concentrated treatment chemicals, and in-line diaphragm serviceability are standard specification requirements for chemical feed valve selection at the mainline size; gray PVC body construction satisfies the Schedule 80-equivalent material requirements of water treatment plant chemical feed piping specifications
• Pool & Spa — Chemical Feed Headers & Commercial Systems — Used on 1-1/2" primary chemical feed headers, sodium hypochlorite and muriatic acid distribution mains, and primary chemical injection point isolation valves at large commercial pools, water parks, and aquatic centers where chemical feed systems operate at the 1-1/2" mainline size; diaphragm valve construction eliminates the metal corrosion and chemical contamination that rapidly degrade brass and stainless steel valve performance in continuous chlorine and acid pool chemical service, and multi-turn throttling allows precise chemical feed rate control across the full 1-1/2" mainline flow range
• Industrial Chemical Processing — Installed on 1-1/2" chemical transfer mains, reagent supply headers, process chemical distribution trunks, and acid and caustic primary feed lines in chemical manufacturing, pharmaceutical support, food processing support, and industrial chemical processing environments where a 1-1/2" primary chemical line requires a valve that provides complete fluid isolation, handles the chemical's specific aggressive properties without contamination or corrosion risk, throttles accurately across the full flow range, and can be serviced in-line without removing the valve body from the pipeline
• Irrigation — Chemical Injection Mains — Used on 1-1/2" fertigation and chemical injection headers in commercial agricultural and greenhouse operations where fertilizers, acidifiers, and pesticide solutions are injected into the irrigation main at commercial volumes; diaphragm valve construction tolerates the particulate, viscous, and corrosive properties of agricultural chemical concentrates that rapidly degrade and plug ball and gate valve internals; multi-turn control allows precise injection rate adjustment, and true union serviceability supports the routine diaphragm maintenance schedule required in continuous agricultural chemical service
• Pulp, Paper & Industrial Slurry Systems — The weir-type diaphragm design handles slurries, fibrous fluids, and viscous process streams that would lodge in and damage the recessed cavities, seats, and stem packing of ball valves and gate valves; on 1-1/2" slurry and process fluid transfer lines in pulp and paper operations, mining support facilities, and industrial process environments where fluid characteristics eliminate conventional valve types from the specification, the diaphragm valve's clean, unobstructed flow path and flexible diaphragm sealing mechanism provide reliable isolation and throttling performance across the full range of difficult fluid conditions
• Laboratory & Pharmaceutical Facility Piping — Used on 1-1/2" process water distribution mains, DI water primary headers, reagent supply trunks, and process chemical primary feed lines in university research, pharmaceutical manufacturing support, and regulated laboratory facilities where the crevice-free weir design, EPDM diaphragm wetted surfaces, and complete absence of metal-to-fluid contact satisfy the process purity, contamination prevention, and material traceability requirements of regulated laboratory and pharmaceutical piping specifications at the 1-1/2" primary distribution size
• Municipal & Industrial Wastewater Treatment — Installed on 1-1/2" chemical feed mains, pH adjustment chemical supply headers, and process chemical distribution lines in wastewater treatment and reclamation facilities where treatment chemicals, digester additives, and dewatering aids are distributed through 1-1/2" primary chemical feed piping; diaphragm valve construction handles the aggressive, variable-composition chemical streams of wastewater treatment service without metal contamination risk, and true union in-line serviceability supports the continuous maintenance schedule required in high-cycle wastewater treatment chemical feed service