Hydraulic flange fittings are essential parts for almost all hydraulic systems. Flange joints are used in many different applications and systems. Flange fittings help to create joints where there would be a limitation of movement, or where there is limited space. In most instances, flange fittings are used with in-line valve systems and water pump sets.
In general hydraulic flanges are made using stainless steel connections. There are typically five common types of connections; pipe threads, bolt, sleeve, nipple and gasket. The most common type of connection is the pipe thread connection. This type of flange is used when there are numerous pipe threads. The common bolt and sleeve connection are generally used for single piece connections where there may be the need for fastening two or more pieces together.
Other types of fittings include the bolt and sleeve and 4-bolt flange connections. Bolt connections are usually used when there are numerous bolts that need to be connected. Sleeve and gasket fitting are used when there needs to be sealing of a connection. O-ring fittings seal the connections between the flange and the piston rod. When a 4-bolt flange is used, then the flange must have at least four connecting bolts.
The 4-bolts are commonly installed with the seal provided with the unit. However, in some cases where this is not possible, then additional o-rings and seals can be used. These are typically installed with the optional double-basted nuts provided with the flange connections.
If you are using 4-bolt hydraulic flange fittings, then you need to make sure that they are installed properly. For these fittings, it is essential to make sure that the cones are seated firmly into their seat. Installation may also require you to use a specific type of low-profile washer, like a hex nut. It is ideal to make use of these washers even if the washers are smaller in size as they help to ensure that the connections are very tight. They help you achieve a secure and solid fit.
There are other types of flange nuts that are available like the code 62 4-bolt flange nuts. These are a special type of nuts that can only be used on certain applications. These are used in industries like automotive, marine and construction. As the name suggests, the holes in this type of flange are pre-drilled for watertight installation. The size and the threading of these nuts are different and so the size of the hole needs to matched up with the diameter of the threads to ensure proper fit.