The Caleffi 342452 is an angled radiator isolation and balancing valve, 1/2 in radiator connection with tailpiece x 3/4 in conical pipe connection. It has no spring-return action: it is adjusted with a 5 mm allen key to shut off flow for isolation or to preset flow for balancing, then covered by a protective cap. It performs no thermostatic control and does not accept a control head.
Best for the return side of a towel warmer or radiator pair, where flow must be preset for balancing and then protected from adjustment.
Specifications from Caleffi datasheet 01009/23 NA (replaces 01009/13 NA). Reviewed August 2026.
Key Features
Isolation and Balancing in One Body
Adjusted to shut off flow for isolation or to modulate flow rate for balancing. Seven full turns of a 5 mm (3/16 in) allen head wrench takes the valve from closed to fully open.
Concealed Preset
The allen head screw sits under a removable protective cap, so a commissioned balancing position cannot be disturbed by occupants.
Pairs with the 338 and 339 Valve Bodies
Fitted on the return leg opposite a 338452 or 339452 thermostatic body to give a complete two-valve radiator connection set with matching connections and finish.
Tailpiece with Rubber Hydraulic Seal
The radiator union carries a shaped EPDM ring that seals without hemp or PTFE tape.
No Spring Return
Unlike a thermostatic body this valve holds its set position mechanically. It is a manual device and takes no control head or actuator.
Chrome-Plated Brass Body
Chrome-plated brass body with peroxide-cured EPDM seals, rated 150 psi (10 bar) and 212°F (100°C).
Technical Specifications
| Product Type | Radiator Isolation and Balancing Valve |
| Series | 342 Series |
| Body Style | Angled |
| Radiator connection | 1/2 in straight thread with EPDM-sealed tailpiece |
| Pipe connection | 3/4 in conical, for Caleffi 437, 681, 682 and NA102 fittings |
| Adjustment | 5 mm (3/16 in) allen head wrench under protective cap |
| Turns from closed to fully open | 7 |
| Body material | Brass, chrome plated |
| Valve control stem | Stainless steel |
| Seals | Peroxide-cured EPDM |
| Cap | ABS, white RAL 9010 |
| Suitable fluids | Water, glycol solutions (30% max.) |
| Maximum working pressure | 150 psi (10 bar) |
| Temperature range | 40 to 212°F (5 to 100°C) |
| Body length | 2-1/8 in |
| Radiator centerline | 7/8 in |
| Overall height | 1-1/2 in |
| Weight | 0.5 lb |
Documentation
Related Products
- Caleffi 338452 : Convertible Angled TRV Body
- Caleffi 339452 : Convertible Straight TRV Body
- Caleffi 387127 : Universal Radiator Tool
- Caleffi 437516 : Compression Fitting 1/2" Copper
Frequently Asked Questions
Does the Caleffi 342452 accept a thermostatic control head?
No. It is a manually adjusted isolation and balancing valve with no spring-return action. It isolates the radiator for service and presets flow for balancing, but performs no thermostatic control and takes no head or actuator.
How is the Caleffi 342452 set?
Remove the protective cap and turn the allen head screw with a 5 mm (3/16 in) allen wrench. Seven full turns takes the valve from closed to fully open. Refit the cap to protect the commissioned setting.
Which valve does the Caleffi 342452 pair with?
It is normally fitted on the return leg opposite a 338452 angled or 339452 straight thermostatic valve body, giving a matched two-valve set for a towel warmer or panel radiator.
Which way round does the Caleffi 342452 install?
With the plug closing against incoming flow, as shown in the datasheet.
What are the pressure and temperature limits of the Caleffi 342452?
Maximum working pressure is 150 psi (10 bar) over a temperature range of 40 to 212°F (5 to 100°C). Suitable for water and glycol solutions to 30 percent.
- Product Type:
- Radiator Isolation and Balancing Valve
- Product Family:
- Isolation and Balancing Valves
- Series:
- 342 Series
- Body Style:
- Angled
- Connection Type:
- Conical
- Connection Size:
- 3/4 in
- Body Material:
- Brass, Chrome Plated
- Max Operating Pressure:
- 150 psi (10 bar)
- Max Medium Temperature:
- 212 deg F (100 deg C)
