The Caleffi 533950HA is a PresCal Compact 533H series pressure reducing valve with a 3/4" Sweat union inlet and 3/4" NPT female outlet. It reduces and stabilises incoming water main pressure to an adjustable outlet setting between 15 and 80 psi, factory set at 45 psi, and is rated to 250 psi maximum working pressure at up to 180°F.
Best for small residential systems and point-of-entry service where a compact, code-listed pressure reducing valve is required above 80 psi supply.
Caleffi 2-Year Limited Warranty. Caleffi North America warrants each Caleffi product free from defects in material and workmanship for two years from the date of shipment or delivery. Repair, replacement or refund of the purchase price is at Caleffi's discretion and is the sole remedy. Full terms are set out in the Caleffi North America Limited Warranty. ZOT Supply is a Caleffi distributor.
Key Features
Removable Self-Contained Cartridge
Diaphragm, filter, seat, shuttle and compensating piston lift out as one pre-assembled unit with its cover, so the valve can be inspected or serviced without leaving the piping. Replacement cartridge 533000H covers both 1/2 and 3/4 inch valves.
35 Mesh Stainless Strainer
An integral 0.51 mm AISI 304 stainless filter sits inside the cartridge, protecting the seat on supply water that carries sediment or pipe debris.
Noise Reducing High Flow Seat
A large flow chamber and uniform flow opening keep internal pressure losses low, which produces the falloff performance the 533H is known for and keeps operation quiet.
Tamper-Resistant Cap Included
A black tamper-resistant cap ships with the valve and replaces the standard cap to conceal the adjustment screw against unauthorised set point changes.
Chloramine-Resistant EPDM
The diaphragm and seals are peroxide-cured EPDM, which resists water treated with chlorine or chloramine for longer service life than standard elastomers.
POSI-STOP Union Inlet
A POSI-STOP union seal on the inlet lets the valve come out for cartridge service without cutting pipe. The outlet is NPT female.
Technical Specifications
| Product Type | Pressure Reducing Valve |
| Product Series | PresCal Compact 533H |
| Valve Type | Diaphragm type |
| Connection Size | 3/4" |
| Inlet Connection | Sweat union |
| Outlet Connection | 3/4" NPT female (FNPT) |
| Union Configuration | Single union, inlet only (POSI-STOP) |
| Outlet Pressure Range | 15-80 psi (100-550 kPa) |
| Factory Setting | 45 psi (300 kPa) |
| Maximum Working Pressure | 250 psi (1700 kPa) |
| Maximum Working Temperature | 180°F (80°C) |
| Suitable Fluids | Water |
| Pressure Gauge | Not included |
| Pressure Gauge Connection | 1/8" NPT female |
| Filter Mesh Size | 0.51 mm (35 mesh), stainless steel AISI 304 |
| Body Material | DZR low-lead forged brass EN 12165 CW724R |
| Cover | Glass reinforced nylon PA6G30 |
| Control Stem | Stainless steel AISI 303 |
| Diaphragm and Seals | Peroxide-cured EPDM |
| Seat | Stainless steel AISI 303 |
| Certifications | ICC-ES certified to ASSE 1003 and CSA B356 (R2015); NSF/ANSI 61 (180°F/82°C Commercial Hot), file PMG-1356; NSF/ANSI 372, file PMG-1360 |
| Code Compliance | IPC, IRC, UPC, NPC |
| Shipping Weight | 2.3 lb |
Specifications taken from Caleffi datasheet 01252/23 NA, installation instructions NA10617.04 and submittal data 03025 NA.
Documentation
Design Resources
Related Products
- Caleffi 533350HA : PresCal Compact Pressure Reducing Valve 3/4" NPT
- Caleffi 533650HA : PresCal Compact Pressure Reducing Valve 3/4" Press
- Caleffi 533750HA : PresCal Compact Pressure Reducing Valve 3/4" PEX Crimp
- Caleffi 533951HA : PresCal Compact Pressure Reducing Valve 3/4" Sweat w/ Gauge
- Caleffi 533000H : Replacement Cartridge, 533H 1/2 and 3/4"
Frequently Asked Questions
What does the Caleffi 533950HA do?
The 533950HA is a PresCal Compact 533H series pressure reducing valve. It lowers incoming water main pressure to a stable, adjustable outlet pressure between 15 and 80 psi, protecting fixtures, appliances and piping. Plumbing codes generally require a pressure reducing valve where static supply pressure exceeds 80 psi.
Is the Caleffi 533950HA certified for potable water?
Yes. It is ICC-ES certified to ASSE 1003 and CSA B356 (R2015), complies with NSF/ANSI 61 for 180°F/82°C Commercial Hot under file PMG-1356, and complies with NSF/ANSI 372 under file PMG-1360. It meets IPC, IRC, UPC and NPC.
What is the maximum working pressure of the Caleffi 533950HA?
250 psi (1700 kPa), at temperatures up to 180°F (80°C). Where the ratio between inlet and outlet pressure is too high for a single valve to control, Caleffi calls for a two-stage arrangement using a 536A series PresCal HP as the first stage.
Does the Caleffi 533950HA include a pressure gauge?
No. A gauge can be fitted to the 1/8" NPT female gauge port. For the same valve with a factory-fitted 0-100 psi outlet gauge, order 533951HA.
Which replacement cartridge fits the Caleffi 533950HA?
Cartridge 533000H fits 533H series valves in both 1/2 and 3/4 inch. It carries the diaphragm, filter, seat, shuttle and compensating piston as one assembly.
How is the set point protected on the Caleffi 533950HA?
A black tamper-resistant cap ships with the valve. Fitted in place of the standard cap it conceals the adjustment screw, which deters unauthorised changes to the delivered pressure.
- Product Type:
- Pressure Reducing Valve
- Valve Type:
- Diaphragm
- Product Series:
- PresCal Compact
- Outlet Pressure Range:
- 15-80 psi
- Pressure Gauge:
- Not Included
- Connection Type:
- Sweat
- Connection Size:
- 3/4 inch
- Union Configuration:
- Single Union
- Certification:
- ASSE 1003
- Max Operating Pressure:
- 250 psi
- Body Material:
- DZR low lead brass
