Valves are only as good as their connections, which are made up of several parts that attach to and link the plumbing. When it comes to installing valves and other process components in piping systems, there are six primary types of connections to choose from, each with advantages and disadvantages:
Threaded \sWelded \sFlanged \sCompression
Consider these variables while deciding on a valve connection:
Standards compliance in the workplace, as well as in industry.
Removal for repairs or replacement Ease of installation
Simplifying the inventory
Prevention of leakage
The valve’s long-term viability
Rating of pressure in the system
For example, a person’s weight and height
The type of connection that works best for your system depends on the characteristics of your computer.
Ball Valves with a Threaded Ball
Valves with threaded connections are one of the most frequent ways to attach valves. The screw-type design of this valve makes it compatible with the piping system. Threaded valve connections can be made in three basic ways:
a relationship in which only females are involved
Male and female
Threaded valve connections ensure a tight seal and a more efficient connection between the valve and the piping system. The majority of valves feature female threaded connectors that fit over the male threaded end of a pipe. To ensure compatibility, both the valve and the pipes must have the same standard thread design.
In terms of installation, maintenance and replacement, ball valves with threaded connections are a great fit for smaller applications. When using a ball valve with a diameter under 4 inches, threaded connections are almost always preferred. As a result of the greater difficulty in sealing bigger diameter connections, leaks via the threads are more common.
Smaller threaded ball valve connections should still be protected with pipe tape or sealant. Sealant functions as a lubricant and prevents metal-to-metal contact and galling by providing more sealing.
Ball Valve Threaded Connections (Straight vs. Tapered Connections)
Thread design is governed by industry norms, as we discussed before. These connections can be straight or tapered and are regulated by three standards: National Pipe Thread, British Standard Pipe, and Metric metric (more on these below).
Straight threaded connections require a washer or a soft O-ring seal to preserve their leak-tightness. Threads with tapered ends, as the name implies, gradually decrease in diameter as they approach the end of the connection While an O-ring may be unnecessary in a tapered connection, it is still necessary to use pipe tape or sealant to provide a leak-tight seal.
The standard for piping thread design in most of North America is the National Pipe Thread (NPT) (excluding Mexico). Straight (NPS) or tapered (NPT) threads are uniform, pitch at a 60-degree angle, and can be straight (NPS) or tapered. In order to form a leak-tight seal, male and female tapered threads must be linked.
ASME B1.20.1 lays forth the requirements for NPT fittings. Following the "NPT" suffix, sizes are categorized by the connection’s diameter in inches (4 NPT).
Pipe Threads of the British Standard (BSP)
Except for the United States and Canada, most countries accept BSP threads. Like NPT, BSP threads can be straight or tapered; they are unified and pitched at a 55-degree angle.
To ensure that the male and female components of a tapered BSP (BSPT) threaded connection are completely sealed against leakage, sealant is required. Thread sealant is not required for straight or parallel BSP (BSPP) threaded connections because the design has a bonded seal.
BS EN 10226-1:2004, BS EN 102266-2:2005, and BS EN 102266-3:2005 are the standards that describe BSP threads. Using the letters R (German for "pipe") and G (gas) for straight and tapered connections, the primary diameter in inches (R 2 12) is stated.
Metric Threading Requirements (M)
ISO M is an international screw thread standard for general purpose. There are no sharp peaks or valleys in the M threads, which are all parallel and pitched at an angle of 60 degrees to each other. ISO 68-1, published in 1947 as one of the ISO’s first standards, lays out the design requirements.
When comparing M, BSP and NPT threads, the main distinction is that M threads are sized in millimeters, whereas BSP and NPT use inches. A hyphen separates the primary diameter and pitch in the size designation (M8-1.25). To measure pitch, measure how far apart two thread crests are from each other in millimeters (mm).
Connecting Valve Ports via Welding
Welding valve connections into a piping system eliminates the chance of leaks.. High-temperature, high-pressure systems, such as those in chemical processing, require for the usage of welded valve connections since any faults that could be caused by leaks are simply not an option. Because the valve must be desoldered before it can be removed from the plumbing, this is typically thought of as a long-term installation.
Connectors for Flanged Valves
Solid metal plates with bolt holes around the valve connection’s edge, and these are known as flanges. To ensure a reliable connection, a flanged valve plate can be fastened to another flange on the pipe. Valves with a diameter more than 4 inches commonly use flanged connections, which are typical in industrial settings. Routine cleaning is a breeze with flanges because they are so simple to install and remove. Flanged connections, like threaded connections, must follow to tight requirements that regulate the plate design, hole size and location, and the kind of thread in the holes (ASME B16.5 – 2020 and ISO 7005-1:2011).
Connections to Compression Valves
Compression connections are classified as one of three types:
It is possible to compress a valve using the old-fashioned method of threading the ferrule into a valve socket, which is accomplished by sliding a nut over the pipe end and then tightening the nut. In order to create a leak-tight seal, the ferrule is squeezed between the valve and the compression nut. Residential plumbing frequently uses compression connections.
Push-to-Connect: There is a little O-ring inside the valve port that is stretched and compressed to fit around the connecting tube, which is slightly smaller in diameter than the valve port itself. The pipe is held in place by a grab-ring with teeth that prevents it from slipping out, however pressing the release ring retracts the teeth, making removal simple. Residential plumbing systems frequently use push-to-connect method
Link to this article：An explanation of the term Valve Connection