Datasheet
Weld-in Socket with Sealing Face for Pressure Gauges – precise, flat-sealing process connection
Weld-in sockets with integrated sealing face provide a flat-sealing female thread (e.g., G 1/4, G 1/2) for pressure gauges, digital gauges, pressure switches, and shut-off valves. The machined sealing face (flat seat/O-ring land) enables a repeatable, low-leak connection—ideal where instruments are serviced frequently or tightness requirements are high.
Available in carbon steel, stainless steel 304/316(L), and special alloys. Options include EN 10204 3.1 material certificates, defined surface roughness (e.g., Ra ≤ 1.6 µm), and preconfigured sets (socket + valve + gauge).
FAQ on Weld-in Sockets with Sealing Face for Gauges
Answers on geometry, standards, materials, welding notes, sealing concepts, pressure/temperature limits, and practical tips.
How does a socket with sealing face differ from a standard weld socket?
| Feature | With sealing face | Standard |
|---|---|---|
| Sealing | Flat gasket/O-ring on machined face | Thread sealing (e.g., PTFE) or tapered |
| Repeatability | Very high (defined seat) | Depends on assembly/sealant |
| Serviceability | Faster, cleaner removal | More effort with frequent changeouts |
Which thread standards are offered?
| Female thread | Standard | Sealing |
|---|---|---|
| G 1/4, G 1/2 | ISO 228 (BSPP, parallel) | Flat gasket/O-ring on face |
| M20×1.5 (optional) | ISO metric | Flat gasket/O-ring per device |
| 1/4" NPT, 1/2" NPT* | ASME B1.20.1 (taper) | *no sealing face; prefer G/metric for flat seats |
What surface finish is recommended for the sealing face?
Typically Ra ≤ 1.6 µm (flatness/parallelism per drawing). Observe chamfers/radii for O-ring lands per manufacturer guidance.
Which materials are suitable?
Carbon steel for neutral media/moderate T; 316(L) for corrosive media/process duty; Duplex/Hastelloy® on request. Select seal materials to match the medium (FKM, EPDM, PTFE, FFKM).
What should be considered when welding?
- Clean joint prep (bevel/degrease), follow WPS/PQR, use qualified welders.
- Limit heat input to avoid distortion (tack welds).
- Avoid reworking the sealing face; for stainless, pickle/passivate after welding.
What pressure/temperature ranges are feasible?
Depends on wall thickness, geometry, material, and plant class (e.g., PED/ASME). For higher pressures, plan larger wall thickness and sufficient weld-in length.
How do I choose between flat gasket and O-ring?
| Criterion | Flat gasket | O-ring |
|---|---|---|
| Assembly | Simple, low cost | Fast, defined squeeze |
| Reusability | Limited | Good (medium/T dependent) |
| Chemical resistance | Choose PTFE/fiber as needed | Elastomer per medium (FKM/EPDM/FFKM) |
How do I prevent leaks at the sealing face?
- Ensure a clean, burr-free face; avoid damage.
- Use the correct gasket/O-ring hardness and size.
- Tighten to the device’s specified torque; clamp evenly.
Is this design suitable for hygienic service?
For hygienic processes use flush faces with low roughness, compliant O-rings (FDA/EU 1935/2004), and low-dead-space flow. Alternatively consider hygienic stubs (Tri-Clamp/Varivent®).
Any specifics for hazardous (Ex) areas?
Provide bonding/grounding, avoid ignition sources. For electrical devices (e.g., contact gauges) use appropriate Ex barriers and observe approvals.
Which tests are recommended?
- Pressure/leak testing of the weld and flat-seal joint
- Optional NDT (VT/PT/RT) per project spec
- EN 10204 3.1 material certificates on request
How should I position the socket in the process?
- Choose a low-turbulence location; ensure representative measurement.
- Leave space for a siphon/cooling section for steam/hot media.
- Plan ergonomics for upright reading and tool access.
Can I adapt to other connections later?
Yes, via adapters (e.g., G → metric). Consider added sealing points and ratings; ideally specify the final thread from the start.
Which common sealing materials are used?
| Seal | Typical temperature range | Properties |
|---|---|---|
| FKM | −20…+200 °C | Broad chemical/oil resistance |
| EPDM | −40…+150 °C | Excellent for aqueous/alkaline media |
| FFKM | −20…+260 °C | Very high chemical/T resistance |
| PTFE flat gasket | −60…+250 °C | Outstanding chemical resistance |
Tips for a durable measuring point
- Protect the weld area from mechanical loads (bracket/support).
- Apply external corrosion protection; passivate stainless steel.
- Include regular visual/leak checks in maintenance plans.
Do you supply pre-assembled sets & documentation?
Yes—ready-to-install sets with sealing-face socket, shut-off valve/snubber, and gauge including 3.1 certificate, leak test, and documentation are available on request.