Metal Seal Archives - RYCO Hydraulics
Hydraulic connector thread forms and their applications

If you’re new to the world of hydraulics, it can seem difficult to gain an understanding of the many hydraulic connectors available today. In this series of articles, you’ll learn about the different types of hydraulic connectors and their key differences, which will assist in making some sense of this complex subject. Factors affecting development of hydraulic connectors Two factors have influenced the development of hydraulic connectors: 1: A reluctance to adopt industrial standards between countries Many of these connector types were developed during the 20th century; a time of fierce industrial competition. Co-operation between the major industrialised countries was limited for many years due to conflict. 2: The evolution of hydraulic systems Hydraulic systems have changed a great deal in a short period of time. Driving this change is the gradual increase of the desired machine output force, which is seen as a pressure increase. In the previous series of articles introducing the three types of hydraulic connectors we discussed three principle types of connectors: Tapered threads Metal seal connectors Soft seal connectors Each major industrial region has developed ...

The three types of hydraulic connectors and their two key functions

This article is an overview of the theory of hydraulic connectors, the three main types of connectors and the two key functions that all hydraulic connectors must fulfil. Three Main Types of Hydraulic Connectors It provides basic information about the three main classes of hydraulic connectors: Tapered Threads Metal seal connectors Soft seal connectors Two Key Functions of Hydraulic Connectors It’s important to understand that there are two functions that a hydraulic connector must fulfil: Holding Sealing Sometimes the holding and sealing functions are provided by the same mechanism, and sometimes by two different parts. Hose connectors may seem very confusing because of the many different types available. However, when looking objectively, connectors will always simply do two things. Hold, and seal under pressure. Development of Hydraulic Connectors Hydraulic connectors were developed in this order: Tapered threads Metal seal connectors Soft seal connectors Tapered Threads Tapered pipe threads were one of the first ways to connect pipes together. They involve cutting the pipe thread in a tapered manner, so that the diameter of the pipe changes over the length of ...

Metal Seal Connectors – A better alternative to tapered threads

Machined faces were added to tapered pipe threads in an effort to address some of the shortcomings of pipe threads. A deep 30 degrees chamfer was added to the face of thread to form a seat. This is a modification that is only really seen in hydraulic products due to the high pressures involved. While a tapered pipe thread is still used, the thread no longer provides the sealing function. The thread now only provides the holding function, which is a fundamental change in its use. The machined face provides the following benefits: Easier orientation Better sealing No need for sealant The 30 degree machined face was first developed for the British pipe thread, BSP. That way the advantages of the sealing on the machine seat are available in the America thread also. Metal Seal Pipe Thread Types British Pipe Threads: British Standard Pipe Taper (BSPT) British Standard Pipe Parallel (BSPP) American Pipe Threads: National Pipe Taper (NPT) Advantages of Metal Seal Pipe Threads These connectors have a greatly reduced leakage when compared with simple pipe threads. Disadvantages of Metal ...

Metal seal hydraulic connectors and their uses

Metal seal connectors use profiled metal surfaces on the connector to form a seal. There are many different types of metal seal connectors, including JIC, DIN, BSPP and JIS, NPSM, and they are used across many industries. JIC Joint Industries Council Country of origin: USA Thread angle: 60 degrees (UNC / I-INF) Seat angle: 37 degrees JIC threads are parallel. The thread used is a unified thread, either course; I-INC, or fine; UNF. JIC are the most popular hydraulic connector form due to their versatility. They can connect to both hose and tube. When connecting to inch tube, it needs to be flared and a tube nut and sleeve, (RYCO part number S6), are required. Metric - DIN 2353 Deutsche Industrie Normen Country of origin: Germany Thread angle: 60 degrees (DIN 3853) Seat angle: 24 degrees They have a 24 degrees internal machined seat. These threads are becoming much more common worldwide. Like the JIC connector, there are DIN threads that can connect to both hose and tube. Unlike all other thread types, there are three sub-groups within the DIN ...