The Caleffi 520500AX is a TankMixer thermostatic mixing valve with 3/4" Male NPT connections, listed to ASSE 1017 and rated 2.0 Cv. It is used for point of distribution temperature control in domestic hot water and hydronic systems.
Best for water heater and storage tank outlets where a single valve sets the distribution temperature for an entire building, zone or riser.
Specifications sourced from Caleffi NA technical literature, 2025 revisions.
Key Features
ASSE 1017 Listed
Certified for point-of-distribution service, controlling water heater outlet temperature for an entire building or zone.
Thermostatic Element Control
A wax-actuated element responds to outlet temperature changes and repositions the shuttle continuously, holding setpoint without power or controls.
Low-Lead Brass Construction
Wetted surfaces carry a weighted average lead content below 0.25%, meeting Section 1417 of the Safe Drinking Water Act.
Technical Specifications
| Connection Size | 3/4" |
| Connection Type | Male NPT |
| Flow Coefficient (Cv) | 2.0 |
| Maximum static operating pressure | 150 psi |
| Adjustment temperature range | 95 - 150 deg F |
| Maximum inlet temperature | 195 deg F |
| Flow rate working range | 0.5 - 9 gpm |
| Certification | ASSE 1017 |
| Series | TankMixer |
| Valve Technology | Thermostatic |
| Shipping Weight | 2.4 lb |
Documentation
Design Resources
Related Products
- Caleffi 520510AX : TankMixer Thermostatic Mixing Valve 3/4" Male NPT
- Caleffi 520506AX : TankMixer Thermostatic Mixing Valve 3/4" Press
- Caleffi 520516AX : TankMixer Thermostatic Mixing Valve 3/4" Press
- Caleffi 520509AX : TankMixer Thermostatic Mixing Valve 3/4" Sweat
Frequently Asked Questions
Is Caleffi 520500AX approved for point-of-distribution service?
Yes. Caleffi 520500AX is listed to ASSE 1017, the standard covering temperature-actuated mixing valves used to control hot water distribution from a water heater or storage tank. ASSE 1017 valves regulate system supply temperature; they are not a substitute for ASSE 1070 point-of-use scald protection at individual fixtures.
What is the temperature adjustment range of Caleffi 520500AX?
The adjustment temperature range is 95 - 150 deg F. Maximum inlet temperature is 195 deg F. Confirm the setpoint against the applicable plumbing code for the installation.
What connection does Caleffi 520500AX use?
Caleffi 520500AX is supplied with 3/4" Male NPT connections. Other connection styles in the TankMixer family are listed under Related Products.
Does Caleffi 520500AX include integral check valves?
No. This model is supplied without integral inlet check valves. Caleffi offers a companion model with a C in the product code for applications that require built-in crossflow protection.
What is the warranty on Caleffi 520500AX?
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:
- TankMixer
- Valve Technology:
- Thermostatic
- Application:
- Point of Distribution
- Connection Type:
- Male NPT
- Connection Size:
- 3/4 inch
- ASSE Listing:
- ASSE 1017
- Flow Coefficient:
- 2.0 Cv
- Integral Check Valves:
- No
- Temperature Gauge:
- No
- Adjustment Temperature Range:
- 95 - 150 deg F