The Caleffi 535971HA is a PresCal pressure reducing valve with 1-1/4" Sweat connections, listed to ASSE 1003, adjustable across 15-90 psi. It reduces incoming supply pressure to a stable outlet pressure for domestic water distribution.
Best for residential and light commercial service entrances requiring code-compliant pressure control.
Specifications sourced from Caleffi North America technical literature. Last reviewed July 2026.
Key Features
ASSE 1003 Listed
Certified to the standard governing water pressure reducing valves for domestic water supply, required by most plumbing codes where supply pressure exceeds 80 psi.
Balanced Diaphragm Design
A diaphragm-actuated seat holds outlet pressure steady as inlet pressure and demand vary, and tolerates sediment-bearing supply water better than a tight-clearance piston.
Integral Pressure Gauge
A built-in outlet gauge confirms delivered pressure during commissioning and service without a separate tapping.
Low-Lead Brass Construction
Wetted surfaces carry a weighted average lead content below 0.25%, meeting Section 1417 of the Safe Drinking Water Act for potable water service.
Technical Specifications
| Product Type | Pressure Reducing Valve |
| Connection Size | 1-1/4" |
| Connection Type | Sweat |
| Valve Type | Diaphragm type |
| Outlet Pressure Range | 15-90 psi |
| Maximum operating pressure | 300 psi |
| Maximum working temperature | 180 deg F |
| Material | DZR low lead brass |
| Certification | ASSE 1003 |
| Pressure Gauge | Included |
| Product Series | PresCal |
| Shipping Weight | 5.7 lb |
Documentation
Design Resources
Related Products
- Caleffi 535370HA : PresCal PRV 1-1/4" NPT
- Caleffi 535371HA : PresCal PRV 1-1/4" NPT w/ Gauge
- Caleffi 535670HA : PresCal PRV 1-1/4" Press
- Caleffi 535671HA : PresCal PRV 1-1/4" Press w/ Gauge
Frequently Asked Questions
What does Caleffi 535971HA do?
Caleffi 535971HA is a pressure reducing valve. It lowers incoming supply pressure to a stable, adjustable outlet pressure, protecting fixtures, appliances and piping. Most plumbing codes require a PRV where supply pressure exceeds 80 psi.
What outlet pressure range does Caleffi 535971HA cover?
The outlet pressure is adjustable across 15-90 psi. Set the outlet to suit the fixtures served and the applicable plumbing code.
Is Caleffi 535971HA ASSE 1003 listed?
Yes. It is listed to ASSE 1003, the standard for water pressure reducing valves in domestic water supply. Confirm acceptance with the authority having jurisdiction, as some jurisdictions add local requirements.
Does Caleffi 535971HA include a pressure gauge?
Yes. This model ships with an integral outlet pressure gauge.
What is the warranty on Caleffi 535971HA?
Caleffi covers this product under its standard two-year limited warranty against defects in material and workmanship from the date of purchase. ZOT Supply is an authorized Caleffi distributor.
- Product Series:
- PresCal
- Product Type:
- Pressure Reducing Valve
- Valve Type:
- Diaphragm
- Connection Type:
- Sweat
- Connection Size:
- 1-1/4 inch
- Pressure Gauge:
- Included
- Certification:
- ASSE 1003
- Outlet Pressure Range:
- 15-90 psi
- Max Operating Pressure:
- 300 psi
- Body Material:
- DZR low lead brass