Safety valve · Supplied by BAUTU
A48Y Spring Loaded Full Lift Safety Valve with Lever — DN25 to DN300
Spring loaded, full lift safety valve with a lifting lever, for steam and air on boilers, pressure vessels and pipelines. When the pressure rises above the set pressure the valve opens fully and discharges; when the pressure falls back it closes again. The lever lets your operators lift the disc by hand to check that the valve is free. DN25 to DN300, PN16 / PN25 / PN40 or ASME Class 150 flanges.
- Supplied by BAUTU, inspected and tested before shipment
- Outlet one size larger than the inlet as standard; same-size outlet on request
- Non-standard sizes, flanges and set pressures made to order
- Material certificate and test report with every shipment
- Standard sizes ship in 15–20 days
An engineer replies within 24 hours. Send inlet size, set pressure, media, temperature and quantity.
Specifications
Technical Data
| Type | Spring loaded, full lift, open bonnet with lifting lever |
| Size range | Inlet DN25–DN300 (NPS 1″–12″) |
| Pressure rating | PN16 / PN25 / PN40 (1.6 / 2.5 / 4.0 MPa) · ASME Class 150 |
| Set pressure | Adjusted to your order |
| Connection | Flanged inlet and outlet · GB / EN PN flanges or ASME B16.5 Class 150 |
| Body material | WCB carbon steel · 304 stainless steel · 316 stainless steel |
| Seat and disc | Hard-alloy faced (letter “Y” in the model code) |
| Working temperature | ≤ 350 °C (carbon steel body) |
| Media | Steam, air and similar gases |
| Lift | Full lift |
| Documents | Material certificate and test report with every shipment |
| Lead time | Standard sizes 15–20 days |
Configurations
Inlet, Outlet and Flange Options
Real photos
A48Y Safety Valves Before Shipment
STAINLESS · DN80 PN16
READY FOR SHIPMENTWITH LIFTING LEVERHow to read the model
Model Code A48Y-16C
Dimensions
Dimensions (mm)
| Inlet DN | Throat d0 | L | L1 | Outlet DN′ | H | Weight (kg) |
|---|---|---|---|---|---|---|
| 25 | 15 | 110 | 95 | 32 | 325 | 10.5 |
| 32 | 20 | 115 | 100 | 40 | 325 | 12.2 |
| 40 | 25 | 120 | 110 | 50 | 330 | 15.5 |
| 50 | 32 | 135 | 120 | 65 | 340 | 20 |
| 65 | 40 | 160 | 140 | 80 | 425 | 30 |
| 80 | 50 | 170 | 135 | 100 | 445 | 33.5 |
| 100 | 65 | 195 | 175 | 125 | 565 | 58.5 |
| 150 | 100 | 255 | 230 | 175 | 660 | 102 |
| 150 | 100 | 255 | 230 | 200 | 735 | 110 |
| 200 | 125 | 300 | 260 | 250 | 795 | 179 |
| 250 | 150 | 350 | 320 | 300 | 975 | 370 |
| 300 | 200 | 380 | 350 | 400 | 1235 | 550 |
Unit: mm. Carbon steel body with GB PN flanges. L: inlet centreline to outlet flange face · L1: inlet flange face to outlet centreline · H: overall height. Drawings for ASME Class 150 flanges, stainless steel bodies and non-standard sizes are sent with your quotation.
Pressure & temperature
Models by Body Material
| Model | Body | Pressure | Max. temperature | Media |
|---|---|---|---|---|
| A48Y-16C / 25C / 40C | WCB carbon steel | PN16 / 25 / 40 | ≤ 350 °C | Steam, air |
| A48Y-16P / 25P / 40P | 304 stainless | PN16 / 25 / 40 | To order | Steam, air, corrosive gases |
| A48Y-16R / 25R / 40R | 316 stainless | PN16 / 25 / 40 | To order | Steam, air, corrosive gases |
The set pressure is adjusted to your order within the rating of the PN or Class you choose.
How to order
Send Us These 8 Details for a Fast Quote
- Inlet size (DN or NPS)
- Outlet size, or “standard”
- Set pressure
- Media
- Working temperature
- Flange standard: PN16 / 25 / 40 or ASME Class 150
- Body material: WCB, 304 or 316
- Quantity and destination port
FAQ
Frequently Asked Questions
What is the difference between the A48Y and the A42Y safety valve?
The A48Y has an open bonnet with a lifting lever, so the disc can be lifted by hand to test the valve; it is the usual choice for steam. The A42Y has a closed bonnet without a lever, which keeps the discharge sealed inside the valve; it is used for air, gas and petroleum gas, and in stainless steel for corrosive gases.
What does “full lift” mean?
When the valve opens, the disc lifts far enough that the flow area is set by the nozzle throat (d0 in the dimension table), so the valve reaches its full discharge capacity quickly.
Why is the outlet larger than the inlet?
The discharged steam or gas expands, so a larger outlet keeps the back pressure low. As standard the outlet is one size up, for example DN80 inlet × DN100 outlet. A same-size outlet is available on request.
Can you set the valve to our pressure?
Yes. The set pressure is adjusted to your order. State the set pressure, media and temperature in your RFQ.
Can I order non-standard sizes or flanges?
Yes. Non-standard inlet and outlet sizes, flange standards and set pressures are made to order.
Can the A48Y be used for liquids?
These full lift valves are designed for steam, air and gas. For liquid service, send us the media and conditions and we will advise.
What documents ship with the valves?
A material certificate and a test report with every shipment.
