Flange is a device designed for seamless connection of pumps, pipes and valves. This connection method provides an easy way to modifying, cleaning or inspecting the system. Usually, the flanges come with welded or threaded connection; however, the market offers custom stainless steel flanges solutions as well – the firms like AlexanderComley produce both standard and custom-made flanges that meet virtually any requirements.

Flange mounting itself implies using bolts; impermeability is achieved due to gaskets. Industrial flanges are constructed from various materials: with processed surfaces in store, flanges are made from cast iron, stainless steel, brass, plastic, bronze and etc. In addition, flanges, just like pipes and fittings for special application, often have an internal coating of a different quality in comparison with external coating. According to AlexanderComley, bespoke flanges, tubesheet and butt weld fittings uk are oftentimes manufactured from the same material used in the production of pipes.

O-ring and gasket position depends on the implementation of surface and shape of the flange. The most commonly used types are as follows: surface with a projection; groove for the O-ring; flat surface; surface with internal and external thread and tongue and groove joints. It is important that the flange surface are characterised by minor roughness, to ensure the highest quality of the seal. The most widespread types of surface processing are roughing, spiral notching, concentric grooving and smoothing.

To provide the necessary tight flanged connection using gaskets is obligatory. An average gasket is a ring or pressured plates that used for water-resistant mounting. Gaskets are manufactured at extreme temperatures and pressures and are made of non-metallic, semi-metallic and metallic materials. The principle of operation is simple enough: a gasket is clamped between two flanges, and thereby fills the microscopic unevenness and the surface area to prevent leakage of gases and liquids.

Setting Industrial Flanges In A Place

Both standard and bespoke flanges connection is rarely possible without bolts. The number of holes defines the number of bolts, while the length and diameter depend on the class/ type of the flange. As a rule, pipe construction experts use pins, the same types of bolts that are used in building chemical and oil facilities. Pin consists of two screw-nuts and a threaded rod. The second common type is an ordinary bolt with a nut and hex head.

The tricky moments of installation

In order to press for a tight flange connection, a precise gasket installation is obligatory; the bolts should have the right torque time, while single mounting pressure should be distributed throughout the flange. The right moment for bolt tightening provides a perfect opportunity to use its elastic qualities. However, the challenge of defining the right moment for tightening is a part of the process. The challenge is fostered by vibrations in the system as well as creep and thermal expansion of the gasket. When such a loss reaches a critical point, leaks or breaks may occur.

To reduce the risk, the gasket installation process should be paid close attention to. Thus, when installing the gasket the connection should be smooth, mounted in parallel flanges and with little tension. This will improve safety and reduce operating costs. Using grease is another vital aspect that reduces friction when tightening the bolt, increases the lifetime and reduces the tearing off of the bolt during installation. Grease should be applied to the external thread and the surface of the bearing and nut.

Ensuring smooth tightening

To minimise the chance of unexpected issues, the specialists go through a check-list and:

  • Clean the surface to avoid scratches and defects
  • Remove burrs from the threads
  • Inspect all the bolts and screw-nuts
  • Lubricate the surface of nuts, bolts and/or studs.
  • Install a new gasket and make sure its position is calibrated well.

All the checks must be performed with no regard to the type of flanges connection.