Water pressure regulator PRD4HP

diaphragmthree-stageEPDM

Description
Compact three-stage diaphragm regulator PRD4HP designed for accurate regulation of high‑pressure fluids down to very low outlet pressures and low flow rates. The PRD4HP upgrades the PRD3HP first stage with a PEEK valve seat for improved high‑temperature performance while maintaining the same external dimensions and mounting layout for drop‑in replacement.

Key features

• Three-stage diaphragm design for stable outlet pressure despite wide inlet swings
• High‑pressure first stage with PEEK valve seat for enhanced temperature resistance
• Large valve-to-sensing area ratio and low‑friction diaphragm for precise low‑pressure control (suitable to ~0.5 psi)
• Non‑relieving design optimized for accurate low‑flow, low‑pressure control from cylinder or high‑pressure sources

Flow & performance
Maximum inlet pressure: 3,000 psi. Configurable maximum outlet range up to 0–40 psig. Intended for applications requiring precise regulation at very low outlet pressures and flows. Porting: 1/4‑28 internal threaded inlet; 10‑32 internal threaded outlet.

Available configurations

• Adjustment style on cap:
  • [1] Slotted screw with 3/16 in hexagonal lock nut
  • [2] Knurled knob with 3/16 in hexagonal lock nut
  • [3] Knurled knob with 3/4 in dia knurled lock disc
  • [4] Slotted screw with 3/4 in dia knurled lock disc
• Body style:
  • [1] Standard body
  • [2] 10‑32 panel mount version
  • [6] 2 in high resolution diaphragm cap
  • [7] 15/32‑32 panel mount with 2 in high resolution diaphragm
• Outlet pressure ranges:
  • [0] 0 to 5 psig (0.3 bar)
  • [1] 0 to 10 psig (0.7 bar)
  • [2] 0 to 20 psig (1.4 bar)
  • [3] 0 to 30 psig (2.1 bar)
  • [4] 0 to 40 psig (2.8 bar)
• Body materials:
  • Brass
  • [6] 316 stainless steel
• Seal and diaphragm materials:
  • Buna‑N
  • [V] Fluorocarbon (FKM, Viton®)
  • [E] EPDM
  • [EB] Black EPDM
  • [H] HNBR
• Cleaning options:
  • Standard cleaning
  • [I] Instrument grade cleaning
• Lubrication options:
  • Standard lubrication
  • [K] Krytox 240AZ lubrication

Documentation
Flow curves and performance documentation available for PRD4HP (refer to flow curve and performance PDF files).

Technical specifications

• Model: PRD4HP
• Type: Three‑stage diaphragm regulator (non‑relieving)
• Maximum inlet pressure: 3,000 psi
• Outlet pressure range: configurable up to 0–40 psig (ranges available down to 0–5 psig)
• Low‑pressure capability: suitable for regulation around 0.5 psi
• Porting: 1/4‑28 internal inlet, 10‑32 internal outlet
• Approximate weight: ~85 g (brass and stainless steel 303 & 316); +50–60 g with 2 in high resolution cap
• Body materials: Brass or 316 stainless steel
• Seal/diaphragm materials: Buna‑N, FKM (Viton®), EPDM, Black EPDM, HNBR
• First stage seat: PEEK for improved high temperature performance
• Designed for direct cylinder and other high‑pressure sources requiring low‑pressure control