An impermeable virgin PTFE or FKM isolating membrane completely seals off the electromagnetic core tube, preventing fluid contact with metallic plungers and springs.

All fluid-wetted components consist solely of virgin thermoplastics and fluoropolymers, preventing metal leaching and particulate contamination in high-purity chemical lines.

Direct-acting and pivoted rocker mechanisms lift the seal mechanically, ensuring reliable open/close cycling under zero line pressure, gravity drainage, and vacuum loops.

Streamlined internal chamber geometry eliminates dead pockets, preventing chemical crystallization and salt precipitation when metering sodium hypochlorite or brine.

Class H vacuum-impregnated epoxy coils endure non-stop energization in humid, aggressive acid fume environments without overheating or magnetic drop-off.

Double union nuts on UPVC and PVDF models allow the central valve body and coil assembly to be unthreaded from piping without cutting or disassembling solvent-welded lines.

Q1: How does an isolating diaphragm protect the solenoid valve from aggressive acid failure?

In standard valves, process fluid fills the armature guide tube and contacts the stainless steel core and return spring. Even high-grade stainless steels corrode rapidly in hydrochloric acid or bleach. Delco’s isolating diaphragm creates a physical barrier: the magnetic plunger actuates the diaphragm from the dry side, so only the inert polymer body and diaphragm touch the acid.

Q2: Why are anti-corrosion solenoid valves rated to 0.6 MPa (6 Bar) rather than standard 1.6 MPa?

Thermoplastic bodies (UPVC, PVDF, PTFE) have lower tensile strength than cast metals. Furthermore, direct-acting diaphragm isolation designs require the coil’s magnetic pull to directly lift the flexible diaphragm against line pressure without pilot hole assistance. A 0.6 MPa (6 Bar / 87 psi) rating provides the optimum balance of coil safety, thermal life, and structural integrity.

Q3: Can these valves handle sodium hypochlorite (bleach) without sticking?

Yes. Sodium hypochlorite releases chlorine gas bubbles and deposits salt crystals that jam conventional valves. Delco’s anti-corrosion valves feature smooth, deadleg-free flow paths and resilient PTFE/FKM diaphragms that flex during each cycle, naturally dislodging salt crystallization and preventing plunger binding.

Q4: How do I choose between PTFE, PVDF, and UPVC body materials?

Select UPVC for economical ambient temperature (≤ 60°C) chemical dosing, wastewater treatment, and dilute acids. Select PVDF for higher temperatures (≤ 100°C), strong oxidizers like wet chlorine, ozone, or ultra-pure deionized water. Select PTFE for extreme universal chemical resistance (pH 0–14), aggressive mixed organic solvents, and concentrated nitric or hydrofluoric acids up to 120°C.