Valves: What to Look for When Buying One
One of the most important pieces of mechanical equipment is the valve. This device, once a fairly simple metal flap, has evolved into a complex piece of machinery. Even so, the value of valves and their role has never changed. Let’s go over what you should look for when buying one.
What is a Valve?
In the simplest terms, a valve is a device that controls the flow as well as the pressure in a fluid system. Valves come in many shapes and sizes but there are two key roles they serve. One key role is that of the shut-off valve, where the valve stops the circulation of fluids in a system. These valves come in forms like ball valves and knife gate valves. In the other, they control the pressure of the system. These are valves like butterfly valves, globe valves, and needle valves.
What to Keep in Mind
There are several key factors to consider when looking for a valve to install in addition to the purpose of the valve. Vital to choosing the proper valve is knowing what the pressure of the system will be. This is important because an undersized valve might cause the system to leak or most catastrophically rupture while an oversized valve won’t work either.
You also must consider the temperature of the system. Different valves are rated to work for different extreme temperatures. In particular, the manufacture, closure system, and seals should stand up to the most intense temperatures offered.
Also highly important is the flow rate and velocity. This is determined by taking the flow factor, a value given by the manufacturer, and using it to calculate the flow rate using charts provided. This rate is either given in liters per minute or cubic meters per hour.
With these factors in mind and the purpose of the valves decided, here are some of the different types of valves that will suit your needs.
One of the most classic types of valves, a ball valve is used to prevent fluids from circulating in a system. The valve is a quarter-turn valve with a sphere with a hole that when rotated 90 degrees affects the flow. When fully open, the system has an unobstructed flow. When closed, the system is firmly sealed. These valves are known as sector valves when they are 3-way or 4-way valves. They do have an issue at times with excessive fluid pressure. A ball valve is a simple but effective tool.
A knife-gate valve is a valve with a blade in the center. These blades can operate both as shut-off valves or as control valves. They’re extremely useful for dealing with fluids loaded with particles such as pulp. In fact, the valves were originally designed for the pulp industry. Today, they’re heavily favored by industries like petroleum and wastewater since the knife in a knife-gate valve can cut through the thick fluid fast. Knife-gate valves require regular maintenance to their shutters and seals and have slow operations, but for their purposes, they’re a must.
Simple and inexpensive, butterfly valves are among the most popular valves to regulate flow. A butterfly valve consists of a rod with a disc in the center that can be used to control the speed at which fluids pass through the system. The valves operate on a quarter turn system. These can handle a diverse level of fluids from sludge and wastewater to oil and water. Butterfly valves operate poorly in systems with solid particles however as they can’t close fully. The valves are compact with only the most minimal space requirements, another major positive for the devices. They also provide tight seals. A butterfly valve truly is one of the most trustworthy valves on the market.
Globe or piston valves are popular options for regulating flow as well as pressure. The valves were originally named for their spherical shape, though they come in many different shapes now. The valve contains a piston in the center which stops the fluid’s flow. These valves are used for regulating pressure. They often have a spring to allow for adjustment to the pressure. However, with pressure too high, it can be difficult to operate them. Theis type of valve may also suffer from significant head loss as a result of the intense wear and tear. Despite these issues, globe valves are highly effective and can be a great choice for many projects.
Needle valves are one of the smaller valves on the market, making them ideal for low flow systems. These valves are usually manually operated, unlike some others which can be automated. Needle valves are low-cost valves that have a tapered pin to open a space for very precise control of flow. The flow is controlled using a spindle. With the turns required, the spindle is regulated to the finest level.
With many valves on the market, from ball valves to knife-gate valves, it’s important to figure out what you need to make sure your project is what it needs to be. As a leading supplier of valves, we at Valtorc are here to find the exact valve you need for your product. We have a wide variety of valves with all of the information you need as we include full spec sheets and product information for anyone interested. We offer everything from product catalogs to videos to make sure you have all the knowledge you need before making a purchase.
Valtorc is proud of our over 40 years in the valve business. We provide every major type of valve to suit your needs. We provide actuation packages and devices to automate your valves. Contact us today!