Tapered Pipe Archives - RYCO Hydraulics
Tapered Pipe Threads – The earliest hydraulic connectors

Pipe threads were invented to join pipes together. Pipe threads are cut into a tapered form, which means that the diameter changes over its length. The taper is usually a gain of ¾” diameter or 12” of length (or 1 degree 47 minutes). Tapered threads were among the first methods of sealing a threaded connector. The threads pull and hold the parts together, and also provide the method of sealing. The thread is cut to a taper. In this way, the threads will “take up” the gap between the male and female components as they are screwed together. Sealing on a thread is an older method, and as a consequence, has become less preferred. Problems with Tapered Pipe Threads Some of the problems that pipe threads create are: Leaks The sealant may cause blockages Orientation is sometimes difficult Pipe threads cannot accept tube Let’s look at each of these points more closely. Leaks with Pipe Threads Once the threads are screwed together, the thread will bind and seal on the flanks. However, even though there is a close assembly of ...

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 ...

Tapered pipe thread hydraulic connectors – BSPT and NPTF

Tapered pipe thread hydraulic connectors have an outside diameter that is cut on a cone. This results in sides that are not parallel. Two common types of tapered thread connectors are BSPT and NPTF. BSPT British Standard Pipe Taper Country of origin: Britain Thread angle: 55 degrees (Whitworth) Seat angle: 30 degrees BSPT is a tapered thread. This means that the outside diameter of the thread is cut on a cone. The sides are not parallel. The taper angle is a rise of 3/4" for every 12" in length. This is approximately 1 degree, 47 minutes. Male BSPT threads mate with female BSPT threads in adaptors. BSPT female threads are also used in port applications. As BSPT ports seal directly on the thread, the only machining required is drilling the hole and tapping the thread. BSPT threads can also be used as a machined seat connector. The thread used in the female swivel is parallel, BSPP. This is so that the connector bottoms out onto the sealing face. The female swivel is made as a two part assembly. The majority ...