BS4504 Plate Flange

Overview

BS 4504 Plate Flange (Type 01) is a flat plate–type flange manufactured in accordance with British Standard BS 4504. It is produced from steel plate by cutting and precision machining, with accurately drilled bolt holes and a machined sealing surface.

This flange type is widely used in water supply, fire protection, HVAC, and general industrial piping systems, covering pressure ratings from PN6 to PN40, making it suitable for a wide range of operating conditions.

Product Description

BS 4504 Plate (Type 01) Flanges are flat flanges without a hub, designed for welding directly to the pipe end or for use as backing flanges in flanged joints.
The BS 4504 standard defines flange dimensions based on PN pressure ratings, including PN6, PN10, PN16, PN25, and PN40, ensuring compatibility with British-standard pipeline systems.

Although BS 4504 has been largely harmonized into EN standards, it is still commonly specified in existing installations, maintenance projects, and engineering drawings.

Typical specifications:

• Standard: BS 4504

• Type: Plate Flange (Type 01)

• Pressure ratings: PN6 / PN10 / PN16 / PN25 / PN40

• Size range: DN15 – DN2000

• Facing types: FF (Flat Face), RF (Raised Face)

• Materials: Carbon Steel, Stainless Steel

• Manufacturing process: Plate cutting + CNC machining

  
  

Flange production process

Factory Showcase

Installation Instructions

To ensure safe operation and reliable sealing, follow the steps below:

1. Verify Specifications
   Confirm size, table rating (D/E/F/H), material, and bolt pattern match the mating flange.

2. Inspect Flange Faces
   Ensure sealing surfaces are clean, smooth, and free from scratches or debris.

3. Select Suitable Gasket
   Choose gasket material based on pressure, temperature, and service medium
   (rubber, CNAF, PTFE, or spiral wound gasket).

4. Align Bolt Holes
   Position the blank plate flange accurately against the mating flange.

5. Tighten Bolts Evenly
   Use a cross-tightening sequence and apply torque gradually and uniformly.

6. Leak & Pressure Testing
   Conduct hydrostatic or pneumatic testing after installation to confirm sealing integrity.

Note: Always follow recommended torque values and gasket manufacturer guidelines.

FAQ

Q1: What does “Plate / Type 01” mean in BS 4504?

It refers to a flat plate flange without a hub, manufactured from steel plate, similar in concept to EN 1092-1 Type 01 flanges.

Q2: What is the difference between PN6, PN10, PN16, PN25, and PN40?

These PN ratings define the maximum allowable pressure at a reference temperature.
Higher PN ratings correspond to thicker flanges and stronger bolting requirements.

Q3: Is BS 4504 interchangeable with EN 1092-1?

Some dimensions are similar, but BS 4504 and EN 1092-1 are not always fully interchangeable. Always follow the standard specified in the project documentation.

Q4: What facing types are available?

• FF (Flat Face) – commonly used in waterworks and ductile iron systems

• RF (Raised Face) – used in steel piping systems depending on gasket design

Q5: What materials can be supplied?

• Carbon steel – for water, fire protection, and general service

• Stainless steel – for corrosive or special applications

Material grades can be supplied according to project specifications.

Q6: Typical applications?

• Municipal water supply pipelines

• Fire protection systems

• HVAC installations

• General industrial and utility piping