What did you know about Knife Gate Valve

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What did you know about Knife Gate Valve

knife gate valve

Knife Gate Valve are usually installed vertically, so why a knife can be placed horizontally?

Use the Knife Gate Valve on the wider horizontal plane than you can expect. For example, a horizontal installation would be beneficial when installing vertical tubes and experiencing distances, and when using different types of vehicles.

The original knife door was designed to lie along the vertical, so there are some considerations to be made and the challenges faced when fitting the valves horizontally, especially the 18 inch and larger valves.


Knife Gate Valve are installed horizontally when installing vertical pipes, transporting dry solids, pellets and powders, and by discharging dry materials, flowing freely from containers, mixers and silos.

The available space around the valve installed also affects the situation; Sometimes there is no option but to place the valve horizontally because the space is not full.

Engineers provide solutions to these challenges with different design techniques to provide proper operation. With a knife side located next to it, the port needs support when the pack is hit by the weight of the port on the gravity side.

There are two basic support areas:

(1) inside the valve body and (2) outside on the yoke. Both racks may be needed, even if the door is open and closed.

Depending on the application and type of Knife Gate Valve, there are different ways to design support requirements: use thicker materials, harden the body or build a more substantial yoke. The basic reason behind these modifications is to keep the door straight for the best seat seals.

Additional supplements include internal hardening support strips and external support in the regional area.

Valves can be designed to support heavy duty drives, but due to the influence of oscillation, it is always advisable that the drives be supported when the body and yoke are horizontal.

There are two planes that can accommodate the Knife Gate Valve: on the edge and across. The two diagrams below show how the support is integrated in the design of the two aircraft.

Knife Gate Valve of 18 inch and larger provide excellent service placed on the edge or horizontally, when additional support for ports and Knife Gate Valve is designed to match the service orientation and service of the valve.

These special considerations of support are needed to keep the port in line and provide the best possible packaging and seating, whether the specifications are round, square or rectangular, or capped or not. hat. The contractor should seek a specialized manufacturer of custom Knife Gate Valve.

2. Maintenance and Repair of Knife Gate Valve

Knife Gate Valve are used to provide isolation in a variety of applications including sludge, pulp, wastewater and power generation. This is one of the simplest valve designs, and with just a moving part, preventative maintenance schedules are simple.

1. Adjust the packaging once a month.

2. Lubricate trunk and branches every three months. This should be done using a grase gun at the top of the fat at the top of the yolk.

3. Once a year, lubricate the operator.


When the Knife Gate Valve is not used for a long time, the valve must be pedaled at least once every six months, and if in the warehouse, the package should be loosened to extend the life of the package.

It is also important to tighten the glands if needed. When adjusting the packing on the Knife Gate Valve with four or more bolts, it is best to tighten the bolts evenly on both sides of the packing line using the torque method. Normally, a small amount of tightening is required.

Do not over tighten to prevent leaks; Try to align the gland in a uniform way to avoid the possibility of fatty glands rubbing the glands as it moves.

With regular checks and lubrications, depending on the amount of cycles and chemicals in play, the operator will see when to replace the package or seat. If maintenance is needed, safety first:

1. Turn off all operating lines into the Knife Gate Valve.

2. Isolate van completely from the process.

3. Release process pressure.

4. Pour the process fluid from the Knife Gate Valve.


Standard packaging kits are available from knives manufacturers and distributors. Packaging includes the packaging required to ensure a sealed seal. When ordering, you must specify the Knife Gate Valve model number, seat type and valve type. Safety first: Drop the pressure from the Knife Gate Valve and make sure it is closed.

1. Remove the nuts and bolts.

2. Lift the Knife Gate Valve to the fully open position.

3 Drag the package to the top of the door and hold it to the top of the Knife Gate Valve.

4. Use a packing or screw driver, remove all old packaging.

5. Carefully clean the package.

6. Use pre-packaged packaging, one-time packaging on the package. Push down each row of packaging into position using the flat bar tool. The packing slots should be 180 ° apart.

7. Pull the package down and tighten the nuts and bolts by the torque method. DO NOT BE CONFIRMED.

8. Bring the Knife Gate Valve up to the working pressure and tighten the packing gland just enough to prevent any leakage or dripping. By tightening the gland will reduce the packing time.


To replace the seat, first remove the Knife Gate Valve from the line.

Two-dimensional perimeter chair

1. Disconnect the stem from the door and remove the yoke and stem. Remove packaging, packing and valve door.

2. To remove the seat cover, be sure to grip the chair and metal straps with a pair of hand grips and may be assisted to pull the chair out of the Knife Gate Valve body. At the bottom of the valve, the seat grooves have bottom racks and rubber seats must be pulled through the slots.

3. To install a new seat and close the Knife Gate Valve, a reverse procedure is required. First insert a new seat into the cavity of the Knife Gate Valve body by folding the seat into a horseshoe shape and inserting into the seat cavity. Length of three or four foot flat bars is approximately 3/8-inch x 2 or 3 inches and touches as firmly as possible at the bottom of the Knife Gate Valve and along the sides.

4. When the seat is in place with the end of each side protruding above the packing box, insert the valve door.

Assemble and install the antenna, and move the Knife Gate Valve to its bottom, ensuring that the seat is pushed into its groove around the bottom and along the sides.

5. When the chair is firmly in place, remove the yoke and body. Close the Knife Gate Valve, place the strips on each side of the Knife Gate Valve for the full length of the package. Make sure the packaging is cut long enough and fit closely with each end of the packaging. When the Knife Gate Valve is fully packed, take an iron saw and cut out the excess rubber seat on the packing box on each side.

6. Install the package and reassemble it.

7. Shut off the engine through a full cycle and ensure easy operation and no rubbing on the body or packing the gland on the door.

8. Under pressure, tighten the packing bolts just enough to stop closing the leak.

2.4 Procedure for replacing the seat with an O-ring

To change the seat seals for the O-ring, it is necessary to have access to the Knife Gate Valve by removing the valve from the chain or by accessing the Knife Gate Valve on the line.

1. Turn the Knife Gate Valve for the fully open position.

2. Remove the old O-ring and shave any residue that has accumulated in the O-ring groove in the chair. Make sure the O-ring groove is completely cleaned before continuing.

3. Insert new O-rings as follows:

a) Note that the new O-ring diameter is smaller than the O-ring diameter. This allows the O-ring to be slightly stretched when installed in the groove. Lubricate the grooves with a little oil. O-ring will have a bonded joint. Make sure the fitting is installed around 6am.

b) Push a portion of 1 to 2 inches of the O-ring into the groove at 12:00. The groove is a rectangle so it is wider at the bottom of the groove than at the top. The O-ring can be a bit tight at the top.

c) Gently tighten the O-ring, and find the point on the O-ring exactly half the distance from 12:00. Push the O-ring approximately 1 to 2 inches into the groove at 6 o’clock. Make sure there is an equal length of O-ring between 12:00 and 6:00 pm position, on both sides.

d) Now do the same at 3 o’clock and the 9 o’clock position, always making sure the same length on both sides of the point where the O-ring is pushed into the chair.

e) Continue this work by pushing the O-ring into the groove between the two O-rings that have been installed.

f) Once the O-ring has been fully installed, check that it is evenly distributed in the groove. If there are places where the O-ring looks thicker elsewhere, then use a round wooden board or plastic to even contradict.

g) Lubricate the face of the chair and O ring with silicone grease.