Ball Valve  installation instructions:

Do not use this valve in flammable gas (natural gas) installations.
Fluid pressure must not exceed the pressure that is stated on the valve. The fluid temperature of the Teflon used as an imperviousness gasket must not pass 150°C for more than a short period of time and 120°C for longer time periods.
Clean all kinds of foreign substances (sand, gravel, dirt, etc.) from the installation before assembling.

Fit dirt separators (filters) on the suitable parts of the installation for future protection of the valve from dirt and foreign substances.

Only take out the flange from its packaging when you are going to attach it to the installation.

The pipeline should be free of tension before installation commences.
Do not carry the valve from it’s arms.

Verify that the distance between the flanges, where the valve will be connected, is equal to the length of the valve body.

Firstly, fit the impervious gasket between the valve flange and the installation flange. Then mount one side of the valve and only lightly fit the bolts. Do not fully tighten the bolts yet. Similarly, mount the other side of the valve. Finish by uniformly tightening the bolts, to avoid twisting the valve body, on both sides of the valve Set the valve in a fully open or fully closed position as required.

Close and open the valve once a week to prevent the occurrence of lime and dirt layers on the surface of the sphere when the valve has been in the open/closed position for a long time Only move the arm in the direction of the arrow whilst opening and closing the valve. Do not continue to force the arm, when the cycle is completed, by hanging onto the circumscription pin.

Avoid sudden and quick open/close movements to prevent occurrence of a water-pulling stroke on the spherical valves.
Insulate the valve to prevent damage by the liquid freezing in winter months.
Send damaged valves to the service department.
If there is a leakage under the arm, from the gasket in the no O-ring gasket grouped valves, tighten the turnscrew under the arm in a clockwise direction.