Blog posts of '2020' 'August'

Anix Valve is a wholesale sanitary valve manufacturer based in Houston, TX. Check out our selection at https://anixusa.com/sanitary-stainless-steel-valve

By: Lauryn B.

What is a sanitary valve?

Sanitary valves are used for applications that require cleaning or sterile processes. In order for a valve to be considered sanitary it must not have crevices or cavities that can trap media which bacteria can feed on and multiply. They can be used in dairy, food, pharmaceutical, medical, and chemical applications. Common features that it can do is easy cleaning, it will keep it crevice free, and polish contact surfaces. High quality materials are used so they won’t have corrosion building up. They are also easy to clean and some types are hydraulic, electric, or manual.

Specifications

There are very important specs when dealing with the sanitary valves and what they do, such as diameter, working pressure, and operating temperature. The diameter is measured for the across the inlet and the outlet port. While the working pressure is the pressure gate in which it is able to operate. The operating temperature is the full-required range of ambient operating temperature. For the media types, sanitary valves are constructed so that gases, liquids, and liquids with suspended solids can pass through. 

Materials

The type of materials that sanitary valves are made from are either metal or plastic. Metals such as brass, bronze, copper, cast iron, ductile iron, stainless steel, and steel. While for plastic, they come in PVC (PolyVinyl Chloride) and CPVC. The type of end connections that are installed to the valve are threaded, socket-weld or buttweld, push on, solder end, clamp, grooved end, flangeless wafer-style, lugged, mechanical joint, and flanged. While for the anucated sanitary valves depending on if it's going to be manual or automatic have electric, pneumatic, hydraulic, and manual.

By: Lauryn B.

Anix Valve USA is a valve manufacturer based in Houston, Texas. Find out about our wide selection of check valves at https://anixusa.com/globe-valve

A globe valve and its uses

A globe valve is used for regulating flow in a pipeline, consisting of a movable plug or disc element and a stationary ring seat in a generally spherical body. It gets its name  from their global shaped design. It can be used for manual and automatic operations, for regulating flow or pressure, or for complete shutoffs. When it is fully opened it has a higher pressure loss compared to a ball valve due to the flow of the fluid changing direction in the valve. Most of the time it has a handwheel operation. They are the most common out of all the valves. 

Globe valve vs gate valve

There are quite a few differences between a globe valve and gate valve so this would help with choosing which fits your needs. Globe valves are smaller than a gate valve, with a smaller body compared to its length. Gate valves are more prone to have their disc wear out compared to globe valves due to it frequently closing and opening and the amount of flow resistance coming through. Another difference between the two is that a globe valve can only be installed in one direction while a gate valve can be installed in various directions. Globe valves are used for flow regulation while the gate valves are used for on-off control. The globe valve will have a fluid trapped due to the direction of the flow while the gate valve will have little to no fluid trapped inside. Lastly, gate valves are cheaper than globe valves.

Globe valve vs ball valve

Deciding on a globe valve or ball valve? This section will help. The difference between the two valves is the way they close: globe valves close using a plug (stem) to close and stop the flow, but a ball valve has a gate (ball) that closes and opens the flow. Gate valves are good for letting the fluid flow through, while globe valves are for on and off pressure drops. Globe valves are called stroke valves due to the stem and plug going straight and ball valves are given the name of rotational valves due to the stem and ball turning horizontally.  Ball valves are very durable and usually have excellent shut off even after years of use and are generally preferred over globe valves in shutoff applications. The main limitation for ball valves is proportional control because of the large amount of flow that the ball allows. 

Applications

Globe valves are used in wastewater plants, power plants, and process plants. Those valves are usually put in steam lines, coolant loops, lubrication systems, etc. They are used for shut off and regulation protocols to control how much fluid goes through the valve. There are different types of materials that are used to make the valve, such as cast iron or brass/bronze. These types of materials are used for low pressure settings. While stainless steel is used for higher pressures and temperatures. Usually globes valves are rising stems and those are the most common. The seats and dics can be replaced inside the valve, while bonnets can be removed so you can check them out.

By: Lauryn B.

Anix Valve USA is a valve manufacturer based in Houston, Texas. Find out about our wide selection of check valves at https://anixusa.com/check-valve

What is a check valve?

A check valve is only used for a one directional flow that has 2 ports, an inlet and output. They are commonly known as “one way valves” or “non return valves” since it only flows one way. The main purpose for the valve is to make sure it prevents any backflow in the system. It tends to be cheap, effective, and an easy solution to solve a potential issue.

How it works

Check valves depend on pressure for it to work called cracking pressure. It’s the minimum upstream pressure required to open a check valve enough to allow for detectable flow, a small but steady flow that passes through the valve and out the outlet port. Depending on the design of the valve it can close in different ways, such as the back pressure pushing a gate, ball, diaphragm, or disc against the orifice and sealing it. You also have to make sure the valve is facing the right way, it would usually have an arrow on the housing to tell you the direction of the flow direction. If not installed in the right way, it could back up and cause build up pressure which could cause damage.

Materials

The type of materials used are brass, stainless steel, PVC (Polyvinyl Chloride), and Polypropylene (PP). Brass check valves are commonly used for applications that are using air, water, oil, or fuels. Stainless steel is more resistant to corrosion, heat, low temperature and mechanical properties. PVC check valves are used in irrigation and water management systems. Polypropylene check valves are used for water, aggressive media, and liquid food products. 

Check valve types

There are different types of check valves, the most common one is the spring loaded in-line check valve. Some other ones are spring loaded y, ball, diaphragm, lift, swing, stop, butterfly, wafer, duckbill and foot valve. We’ll talk about a few to get a better understanding of the different types. 

Information about valve types

A spring loaded in-line check valve is common and easy to understand. When the flow goes through the input of the valve, it has enough pressure to push through the cracking pressure and the spring force. It pushes against the disc and allows the flow of the fluid to go on through. When the input pressure is no longer high, the back pressure is then the disc gets pushed back into place and seals the valve shut. This valve prevents pressure surges from happening, and also prevents water hammering from occurring. Some common types of spring loaded are ‘nozzle check valves’ or ‘silent check valves.’ 

Another one is called the spring loaded y and it's similar to the spring loaded valve. The only difference is that the spring and the disc are more at an angle, creating a y-shape, for its design. A ball is seated next to a spring that is close to the orifice. When the pressure from the fluid exceeds the cracking the pressure then the ball is ejected from its seat and allows the flow to go through.  Due to its design, it can be inspected inside and “serviced.” But they are larger and it takes more room when installed into the system. 

Here is just a quick rundown of a few other types. Diaphragm check valves are normally open due to self centering diaphragm, which means it doesn't have cracking pressure. The diaphragm has a rubber diaphragm that flexes the inlet pressure to increase. A lift valve has a guided disc that lifts up from the seat allowing the fluid flow through. This one does have a cracking pressure, it is so the disc can be sealed back into its alignment. A swing valve is usually referred to tilting-disc’ check valves. The disc tends to swing open when the inlet pressure is high enough, but when it decreases the disc will swing shut. A stop valve has more of a manual feature. It acts like a normal check valve and can prevent backflow. There is also another mechanism in case for overriding so it can open and close the valve. A butterfly or wafer valve has a hinge and a spring inside. When the pressure builds up, both sides open. But when it decreases, the disc will seal it shut. A duckbill valve lets the fluid go through a soft tube, almost resembling a beak. As the flow goes through, it opens up , but the beak shape flattens stopping from anything from coming through. A foot valve is a check valve with a strainer on the inlet side. They allow the flow to go in one direction and close it off with a spring.

By: Lauryn B.

Anix Valve USA is a valve manufacturer based in Houston, Texas. Find out about our wide selection at https://anixusa.com/gate-valve

What is a Gate Valve?

Gate valves are used widely for different applications and are suited for both above and below ground installation. The function of the gate valve is to either open or close the path of flow, depending on the position of the stem. It has a very distinct feature: it has an unobstructed passageway which leads to minimal pressure loss over the valve. With this design you can even use a pipe cleaning pig.

Fundamentals of a Gate Valve

The main components of a gate valve are body, seat, gate, stem, bonnet and actuator. How it works is by either turning the gate valve clockwise to open or counterclockwise to close the flow path, which rotates the stem. The stem turns a gate that will fully block or allow the full flow, but it does not control the flow. Gate valves are considered to be multi-turn valves, since you have to turn it more than 360 degrees, to either fully open/or close the valve. When gate valves are fully open then they are full bore, which means the gate and pipeline both have the same opening so nothing can stop the flow from going through.

Circuit function

Gates are either done manually, by fully turning the handwheel to let the flow through, or done by an actuator, which is controlled by a computer system which dictates when the actuator should work.  Also, depending on which stem is threaded, it will be a rising or non-rising one. One type of valve, an outside screw and a yoke are considered as rising stems.There is a nut that revolves around the threaded stem which moves the stem making the gate rise or lower as it spins. A non rising stem is affixed to the actuator and threaded to the gate. The actuator is a separate piece, a modification that you put on top of the valve where the threaded stem starts. But to do this the hand wheel and the drive nut needs to be removed, which will expose the threaded stem, allowing the actuator to move up and down, like a pump. 

Temperature 

Gate valves can even be used for a number of various fluids. Such as portable water, wastewater and neutral liquids when the temperature is between -20 and +70 degrees celsius. It also works for gas when the temperature is between -20 and +60 degrees celsius. 

Types of Gate Valves

There are 3 types of gate valves depending on the disc size, the solid taper wedge, flexible wedge, and split wedge, or parallel disks valve. A solid taper wedge is the most common out of the 3 and mostly used due to its simplicity and strength. A solid wedge can be used in any position, and is suitable for almost every type of fluid, though this type of disk design is prone to leakage, due to the seat alignment and to the pipe loads and thermal expansion. This design is widely used for moderate lower pressure temperature applications. A flexible gate wedge is a one-piece solid disk with a cut around the perimeter. Since it is narrower and shallower, the perimeter on the wedge gives less flexibility and retains strength.  Due to its design, it will get less leaks going through and perform best when thermal binding is possible. They are more widely used in steam systems. The only disadvantage is that line fluid gets stuck to the disk, which can result in corrosion and potentially weaken the disk. A split wedge has 2 solid disks that hold together with a special mechanism, in case one wedge is out of alignment the other wedge could still hold up the disk. They are spring loaded which means it keeps in contact with the seat and gives bi-directional dealing. It's used for handling non-condensing gasses and liquids at normal and high temperatures. But the only problem is when the fluid gets heated, it can't create thermal binding.

Gate Valve Materials

There are various materials used such as carbon steel, cast iron, ductile iron, gunmetal, bronze, alloy steels, stainless steel, and forged steels. Brass and pvc are most commonly used for plumbing services. The material designed for each one depends on the what type of fluid and the temperature.