The Caleffi 338452 is an angled convertible radiator valve body, 1/2 in radiator connection with tailpiece x 3/4 in conical pipe connection, for copper and single or multi-layer PEX pipe. It ships with a manual control knob and is usable as a manual valve straight out of the box; swapping the knob for a Caleffi thermostatic control head converts it to automatic room temperature control.
Best for towel warmer style radiators fed from the wall or floor, where the connection must turn through 90 degrees.
Specifications from Caleffi datasheet 01009/23 NA (replaces 01009/13 NA). Reviewed August 2026.
Key Features
Convertible Manual to Thermostatic
Supplied with a white ABS manual control knob. Turn the knob to position 5 and replace it with a Caleffi 200, 201, 203 or 472 series control head, or a 6564 series actuator, to convert to automatic control. No pipework changes.
Tailpiece with Rubber Hydraulic Seal
The radiator union carries a shaped EPDM ring that seals without hemp or PTFE tape, so the radiator connection is made quickly and can be broken and remade cleanly.
Double-Sealed Stainless Stem
A stainless steel control stem with a double EPDM o-ring seal lets the control head be changed with the system running and under pressure.
Shaped Plug for Proportional Control
The plug profile gives an optimal flow characteristic across the full stroke under proportional thermostatic operation, while the wide seat passage keeps head loss low in manual operation.
Angled Body
Turns the connection through 90 degrees, suiting radiators fed from the wall or the floor below.
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 Valve Body |
| Series | 338 Series |
| Body Style | Angled |
| Operation | Convertible manual to thermostatic |
| 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 |
| Head connection | M30 x 1.5 |
| Body material | Brass, chrome plated |
| Valve control stem | Stainless steel |
| Seals | Peroxide-cured EPDM |
| Control knob and cap | ABS, white RAL 9010 |
| Suitable fluids | Water, glycol solutions (30% max.) |
| Maximum working pressure | 150 psi (10 bar) |
| Max. differential pressure with control head | 15 psi (1 bar) |
| Temperature range | 40 to 212°F (5 to 100°C) |
| Max. Cv with 6564 series actuator | 2.4 |
| Approval | UNI EN 215:1990 combined with 200000 control head |
| Body length | 2-1/8 in |
| Radiator centerline | 7/8 in |
| Height to stem | 2-1/32 in |
| Overall height | 3-15/16 in |
| Weight | 0.5 lb |
Documentation
Related Products
- Caleffi 339452 : Convertible Straight TRV Body
- Caleffi 342452 : Angled Isolation and Balancing Valve
- Caleffi 200000 : Control Head, Built-in Sensor
- Caleffi 437516 : Compression Fitting 1/2" Copper
- Caleffi NA10262 : Adapter Kit to 1/2" Sweat
Frequently Asked Questions
What does the Caleffi 338452 do?
It is the valve body of a two-part radiator valve. It fits between the pipe and the radiator and regulates flow. As supplied it is a manual valve; fitted with a thermostatic control head it becomes an automatic room temperature control.
Does the Caleffi 338452 include a control head?
It includes a manual control knob, not a thermostatic control head. The valve is fully usable as a manual valve on arrival. To convert it, order a Caleffi 200, 201, 203 or 472 series control head, or a 6564 series 24V actuator, and replace the knob.
Does the Caleffi 338452 need PTFE tape or hemp at the radiator?
No. The tailpiece carries a shaped rubber hydraulic seal that makes the radiator connection without additional sealing materials.
What pipe does the Caleffi 338452 connect to?
The 3/4 in conical pipe connection takes Caleffi fittings for copper and single or multi-layer PEX: the 437 series compression fitting, the 681 and 682 series PEX fittings, and the NA102 sweat and NPT adapters.
Which way round does the Caleffi 338452 install?
The valve must be installed with the plug closing against incoming flow. An arrow on the body indicates the correct direction.
- Product Type:
- Radiator Valve Body
- Product Family:
- Radiator Valve Bodies
- Series:
- 338 Series
- Body Style:
- Angled
- Operation:
- Convertible Manual to Thermostatic
- 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)
