ASME B16.36 Flange Standard

Jack screw holes in ASME B16.36 flanges are small threaded holes machined into the flange body, typically located opposite the pressure tap locations. These are not for bolting but for the insertion of jack screws used to separate the flange faces during maintenance.

Key functions of jack screw holes:

1. Allow safe and easy disassembly of the flange joint without damaging the orifice plate or gasket.
2. Provide even pressure release, especially in high-pressure systems.
3. Prevent binding or distortion of bolts during flange separation.

These features are essential in industries where routine inspection or replacement of orifice plates is required, such as in refineries, power plants, and chemical processing units.

Jack screw hole locations and dimensions are standardized under ASME B16.36 and vary by flange size and pressure class.

Yes, ASME B16.36 flanges are fully compatible with standard orifice plates and gasket types commonly used in flow measurement systems. The standard defines the gasket seating surfaces and gasket dimensions required for reliable sealing and accurate differential pressure readings.

Gasket Compatibility:

• Spiral wound gaskets (most common in RF flanges)
• Metal jacketed gaskets
• RTJ ring gaskets (for RTJ face flanges)

Orifice Plate Compatibility:

• Plates are designed to fit between the flange facings with the pressure taps aligned perfectly with the orifice bore.
• B16.36 ensures that orifice plate centering and alignment meet flow measurement accuracy standards.

For best results, always match the gasket material and plate thickness with the process media, pressure class, and flange face type (RF or RTJ).

In ASME B16.36 flanges, tapped holes are precision-machined to allow the installation of pressure taps used in differential pressure flow metering systems. These holes are strategically located to ensure accurate and consistent flow readings.

Key Tapped Hole Positioning Features:

1. Typically located at 180° apart, on the flange's outside diameter, across the orifice bore centerline.
2. Some applications may require 90° orientation, depending on system layout and pressure tapping method.
3. Each tapped hole is designed for NPT or BSP threading based on project specification.
4. The tapped hole depth, diameter, and threading standard must comply strictly with ASME B16.36 dimensions for proper instrumentation fit.

Accurate positioning of tapped holes is critical to ensure precise differential pressure measurement, avoid turbulence, and maintain flow profile integrity across the orifice plate.

Proper installation of ASME B16.36 flanges is essential for achieving accurate flow measurement and maintaining system integrity. These flanges are typically installed in pairs with an orifice plate centered between them and pressure taps aligned correctly.

Installation Guidelines Include:

• Ensure flange faces are aligned with minimal pipe misalignment.
• The orifice plate should be installed with the beveled side facing downstream (for concentric plates).
• Pressure tap holes must be positioned at correct clock angles (e.g., 3 & 9 o'clock for horizontal runs).
• Use the recommended gasket type and thickness per the flange face (RF or RTJ).
• Tighten bolts in a criss-cross sequence to ensure uniform gasket compression.
• Install jack screws (if applicable) to assist in disassembly without damaging components.

Following these steps helps ensure measurement accuracy, prevents leakage, and reduces maintenance frequency.

Yes, ASME B16.36 flanges can be customized with additional features and protective coatings to suit demanding industrial environments, particularly in sectors like offshore oil & gas, chemical processing, and high-temperature steam systems.

Common Customization Options Include:

• Extended necks or integral orifice unions for easier instrumentation access
• Drain and vent ports for high-purity or hazardous systems
• Insulation rings to minimize thermal transfer in cryogenic service
• High-performance coatings such as:
  • PTFE / Xylan for corrosion resistance
  • Hot-Dip Galvanizing for outdoor installations
  • Electroless Nickel Plating for chemical resistance

These enhancements help extend service life, improve system safety, and ensure compatibility with specific process media.

Always confirm that any modification still adheres to the dimensional tolerances and pressure integrity requirements of ASME B16.36.

Nutech Overseas is a leading manufacturer and exporter of ASME B16.36 flanges, supplying high-precision orifice flanges to over 40+ countries across multiple continents. Our flanges are used in flow measurement systems for industries like oil & gas, petrochemical, power generation, and offshore platforms.

Major Export Destinations Include:

• Middle East: UAE, Saudi Arabia, Qatar, Oman, Kuwait, Bahrain
• Southeast Asia: Singapore, Indonesia, Vietnam, Malaysia, Thailand
• Europe: Germany, Spain, Italy, Netherlands, Poland
• Africa: South Africa, Egypt, Nigeria
• North America: USA, Canada, Mexico
• South America: Brazil, Argentina, Chile

All exports are backed by international certifications including EN 10204 3.1/3.2, ISO 9001, PED, and full third-party inspection support from TUV, BV, DNV, or Lloyd's as required.