Description
Product Overview
Spirax Sarco BPT13A is an angled balanced pressure thermostatic steam trap manufactured with a maintainable brass body. Engineered for 90-degree pipeline geometry, it discharges condensate and vents non-condensable gases from steam systems while eliminating the need for separate pipe elbows.
The angled family comprises four specific configurations designed for compact industrial and commercial equipment installations:
- BPT13A: Standard model with angled screwed connections (female BSP or NPT).
- BPT13AX: Angled configuration fitted with an internal stainless steel strainer screen.
- BPT13UA: Angled configuration equipped with a brass union inlet connection for simplified fitting and removal.
- BPT13UAX: Angled configuration combining the union inlet fitting with an internal stainless steel strainer screen.
Each model utilizes a sealed capsule containing a specialized fill liquid. Under startup conditions, the capsule remains contracted and holds the valve open, permitting high-volume air venting. When hot condensate and steam reach the capsule, the internal liquid boils, expanding the capsule against the valve seat to shut off steam loss tightly.
Key Features
- Right-Angle Connection Pattern: Inlet and outlet ports oriented at 90 degrees accommodate equipment drops, coil outlets, and tight cabinet piping without auxiliary fittings.
- Hot Forged Brass Enclosure: Body and cap constructed from BS EN 12165 CW 617N brass for working pressures up to 13 bar g (189 psi g) at 220 °C.
- Inline Serviceability: Hexagonal cap unthreads to grant direct access to internal capsule, spring, spacer plate, seat, and strainer without disconnecting the trap body from pipework.
- Strainer Screen Protection (AX / UAX): ASTM A240 316L stainless steel cylindrical screen protects valve sealing surfaces from pipe scale and debris.
- Union Nut Inlet Options (UA / UAX): Integral brass tailpiece and nut allow swift connection to heat exchangers, steriliser discharges, and tracing headers.
- Multiple Capsule Operating Fills: Available with Standard (STD, ~12 °C sub-cooling), Sub-cooled (SUB, ~24 °C sub-cooling), and Near-To-Steam (NTS, ~4 °C sub-cooling) thermostatic elements.
Technical Specifications
Operating and Design Limits (ISO 6552)
| Parameter | Metric Value | Imperial Value |
|---|---|---|
| Body Design Rating | PN16 | PN16 |
| Maximum Allowable Pressure (PMA) | 16 bar g @ 120 °C | 232 psi g @ 248 °F |
| Maximum Allowable Temperature (TMA) | 250 °C @ 7 bar g | 482 °F @ 102 psi g |
| Minimum Allowable Temperature | -20 °C | -4 °F |
| Maximum Operating Pressure (PMO) | 13 bar g @ 220 °C | 189 psi g @ 428 °F |
| Maximum Operating Temperature (TMO) | 250 °C @ 7 bar g | 482 °F @ 102 psi g |
| Minimum Operating Temperature | 0 °C | 32 °F |
| Maximum Cold Hydraulic Test Pressure | 24 bar g | 348 psi g |
Materials of Construction
| Item No. | Part Name | Material | Standard / Specification |
|---|---|---|---|
| 1 | Body | Brass | BS EN 12165 CW 617N |
| 2 | Cap | Brass | BS EN 12165 CW 617N |
| 3 | ‘O’ Ring | High-fluorine fluorocarbon synthetic rubber | Proprietary |
| 4 | Capsule | Stainless steel | Standard grade |
| 5 | Spring | Stainless steel | BS 2056 302 S26 |
| 6 | Spacer Plate | Stainless steel | BS 1449 304 S16 |
| 7 | Valve Seat | Stainless steel | BS 970 431 S29 |
| 8 | Valve Seat Gasket | Stainless steel | BS 1449 304 S11 |
| 9 | Strainer Screen (AX / UAX) | Stainless steel | ASTM A240 316L |
| 10 | Union Nut & Tailpiece (UA / UAX) | Brass | BS EN 12165 CW 617N |
Dimensions and Weights (Angled Models)
| Model | Pipe Size | A (mm) | B (mm) | C (mm) | D (mm) | E Withdrawal (mm) | Weight (kg) |
|---|---|---|---|---|---|---|---|
| BPT13A / AX | 1/2” | 20 | 38 | 53 | 25 | 55 | 0.40 |
| BPT13A / AX | 3/4” | 27 | 40 | 62 | 25 | 55 | 0.45 |
| BPT13UA / UAX | 1/2” | 20 | 67 | 53 | 25 | 55 | 0.50 |
| BPT13UA / UAX | 3/4” | 27 | 75 | 62 | 25 | 55 | 0.55 |
Note: Screwed connections are available in 3/8”, 1/2”, and 3/4” BSP (BS 21 / ISO 7-1) or NPT.
Applications
- Right-angle drainage legs on low- and medium-pressure steam distribution mains.
- Hospital autoclaves and sterilisers operating with NTS capsules (~4 °C sub-cooling) to prevent water logging while preventing live steam escape.
- Wet steaming ovens and commercial cooking vessels requiring rapid startup deaeration.
- Radiators, unit heaters, and plate heat exchanger coil drain ports requiring 90-degree discharge geometry.
- Vacuum return condensate piping networks utilizing SUB capsules (~24 °C sub-cooling) to recover sensible heat and prevent flash steam cavitation.
- Compliance applications for European Pressure Equipment Directive 2014/68/EU Category SEP handling Group 2 gases and liquids (steam, air, and water).
Installation Guidelines
Spirax Sarco BPT13A must be installed with its capsule situated in a horizontal plane and the cap facing directly upward. Position a cooling leg immediately upstream of the trap inlet to ensure condensate cools sufficiently before contacting the capsule, avoiding condensate backup into the steam equipment.
- Maintain a minimum vertical clearance of 55 mm above the cap to facilitate cover removal during maintenance.
- Fit upstream and downstream isolation valves to allow depressurization and servicing.
- When the trap discharges to open atmosphere, install an exhaust diffuser on the discharge port (refer to TI-P155-02) to attenuate noise and dampen high-velocity spray.
- Before commissioning, purge line debris and open isolation valves gradually to avoid hydraulic shock.
Maintenance and Spare Parts
Isolate the trap and ensure line pressure vents fully to atmosphere. Allow the body to cool below burns threshold before unthreading the cap. The fluorocarbon rubber ‘O’ ring must never be exposed to temperatures exceeding 315 °C due to decomposition into hydrofluoric acid.
Step-by-Step Servicing Procedure
- Unthread cap (2) using a 50 mm A/F spanner.
- Lift out spring (5), thermostatic capsule (4), and spacer plate (6).
- Unscrew valve seat (7) using a 17 mm A/F socket.
- Remove strainer screen (9) on AX / UAX models, then withdraw seat gasket (8).
- Clean screen (9) or fit a replacement. Apply anti-seize compound lightly to seat threads and install with a new seat gasket (8), torquing to 35–40 N m.
- Seat spacer plate (6) centrally over the valve seat. Early plates are unidirectional and must have the highest points uppermost; modern plates can fit either way up.
- Position capsule (4) and install conical spring (5) with its narrow end oriented downward against the capsule body.
- Fit a new ‘O’ ring (3) in the cap groove (or replacement gasket on older designs) and torque cap (2) to 50–60 N m.
Tightening Torques and Spare Kits
| Item | Description | Tool Size | Torque (N m) | Torque (lbf ft) |
|---|---|---|---|---|
| 2 | Cap (‘O’ ring seal) | 50 mm A/F | 50 – 60 | 37 – 44 |
| 2 | Cap (Gasket seal - early models) | 50 mm A/F | 90 – 110 | 66 – 81 |
| 7 | Valve Seat | 17 mm A/F | 35 – 40 | 26 – 29 |
Available Spare Kits:
- Maintenance Kit: Contains items 3, 4, 5, 6, 7, 8, and 9.
- Cap ‘O’ Rings: Packet of 2 x 3 rings (item 3).
- Cap Gaskets (Early models): Packet of 3 gaskets (item 3).
- Strainer Screen Pack: Packet of 3 screens and cap seals (items 3 and 9).
Ordering Example
1 - Spirax Sarco ½” BPT13AX balanced pressure steam trap, BSP threaded connection, brass body with integral strainer, STD capsule, drains condensate at 12°C below saturated steam temperature.