In the great words of fictional character Ron Swanson, “Don’t half-ass two things. Whole ass one thing.”
We’ve skewed this quote to our advantage to talk to you about valves. If you half-ass your effort in choosing a valve that’s right for your material, you might end up replacing it sooner, and continue the cycle of choosing valves that don’t work for you.
If you customize your valve right the first time, it will work much better, and last much longer, making it worth the extra effort.
As such, there are a plethora of options out there to make your valve right for your application—the first time. Check out some of those options below.
Closed End Rotor: This type of rotor has a disc attached to the rotor blades to prevent material from damaging the end plates. It is recommended for flake or chip material.
Open End Rotor: Because there is no disc attach to the rotor here, it is easier to clean and has less material build up. This is a better option for lighter material and in combination with mechanical seals.
Metering Rotor: For extremely controlled flow, this small precision rotor works great with test batches of material.
Staggered Pocket Rotor: This rotor’s 16 offset pockets allow for more uniform, continuous flow.
Reduced Volume Rotor: If material moves too easily, it could choke up the system beyond the valve. This metering rotor reduces the Cubic Foot per Revolution (CFR) inside the valve, slowing down flow.
Adjustable Rotor: With very harsh and abrasive material, rotor tips tend to wear prematurely. With this rotor you can adjust the tips by sliding them up as they wear to keep them compliant and keep rotor-housing clearance as close to their starting point as possible.
Flex Tip Style Rotor: The tips on this type of rotor prevent material jams inside the valve by bending out of the way for material.
Helical Rotor: The helical shape of this rotor is meant to act as a knife if any material gets caught between the rotor and housing. We recommend this type of valve for wood chips.
Radius Pocket Rotor: In order to minimize material build-up, the U-shape of these rotor pockets prevent material from getting stuck in any crevices. This is an excellent valve for sanitary or food grade applications.
Packing gland: These are made from woven fibers and lubricant, and need to be manually pushed into the stuffing box.
Lip and quad seals: These use quad rings or lip gaskets as seal reinforcement. Because they use several layers of seals, leaks only occur when the last row of the seal breaks down.
Teflon shaft seal: A sleeve-style shaft assembly that eliminates static electricity and reduces the friction force between its three, four lobed ring seals and the valve rotor shaft.
Mechanical seals: This type of pressurized seal generally uses air purges that are stronger than the force of the air pressure inside the rotary valve to keep materials away from the seal. Air purge seals allow you to measure air pressure and therefore easily detect if you have any seal leaks through pressure changes.
Coatings can be applied in the housing of your rotor, as well as the endplates. Here are our recommendations for varying types of coatings depending on your application:
- For mild to moderately corrosive materials: Hard Chrome
- For abrasive materials: Heavy plating
- For extremely abrasive materials: Tungsten coating
Inboard bearings: This type of bearing sits inside the housing endplates and, if the seals fail, run the risk of contamination. Therefore, they are non-compliant with NFPA.
Outboard bearings: These sit outside the housing endplate, making a gap between the seal and the bearings. They protect your valve from material build-up and are less of a risk of becoming an ignition source in fires. They are compliant with NFPA.
Chain drive: Side-mounted to the rotor, driving it through a chain and sprocket. Due to the extra parts, there is more opportunity for breakdown, as well as product contamination due to the lubrication required.
Direct drive: Side-mounted to the rotor shaft, direct drives can be put at a higher torque with lower rotations per minute (rpm). There are fewer parts on this type of drive, with no need for lubrication.