Installation and maintenance methods of ball valves

There are two kinds of ball valves: one-way sealing ball valves and two-way sealing ball valves. The former has a direction, if the installation is reversed, the sealing under full differential pressure can not be guaranteed, the latter has no direction. The structure has two-way seal and one-way seal: two-way seal generally has no flow direction requirements, one-way seal has flow direction requirements. Let's take a look at the installation of one-way ball valves.

　Ball valve installation:

　　1. Before operation, you must confirm that the pipeline and the valve has been cleaned.

　　2. Valve actuator operation according to the size of the input signal to drive the valve stem rotation: when the valve rotates 1/4 turn forward (900), the valve is closed. When the valve rotates 1/4 turn (900), the valve opens.

　　3. When the direction indicating arrow of the actuator is parallel to the pipeline, the valve opens; when the arrow is perpendicular to the pipeline, the valve closes.

　　Ball valve maintenance:

　　Longer service life and maintenance free time will depend on several factors: maintaining a harmonious temperature/pressure ratio under normal operating conditions and reasonable corrosion data.

　　NOTE: When the ball valve is closed, fluid pressure remains in the valve body.

　　Prior to maintenance, eliminate piping pressure and keep the valve in the open position.

　　Disconnect power or air supply before maintenance.

　　Remove the actuator from the bracket before maintenance.

　　1. Packing Lock

　　If there is a slight leak in the packing culvert, the stem nut must be locked.

　　NOTE: Do not lock, usually locking 1/4 ring to 1 ring will stop the leak.

　　2. Replace the valve seat and seals.

　　I. Disassembly

　　Leave the valve in the half-open position and flush any hazardous materials that may be inside or outside the valve.

　　Close the ball valve, remove the bolts and nuts from both flanges, and completely remove the valve from the piping.

　　Remove the actuator-actuator, connecting bracket, check washer, stem nut, butterfly spring plate, Genan, wear plate and stem packing in that order.

　　Remove the body cap attachment bolts and nuts, separate the cap from the body and remove the cap gasket.

　Ensure that the ball is in the “closed” position to make it easier to remove it from the body, then remove the seat.

　　Gently push the stem down through the hole in the valve body until it is completely removed, then remove the o-ring and packing ring.

　　Note: Be careful to avoid scratching the stem surface and valve packing seal.

　　b. Reassembly

　　It is strongly recommended that the seat and bonnet gaskets and seals be replaced with spare parts kits.

　　Assemble in reverse order of disassembly and assembly.

　　Cross-lock flange bolts with specified torque.

　　Lock nuts with specified torque.

　　After the actuator is installed, rotate the stem to drive the spool to rotate the corresponding input signal to open and close the valve.