Gate valves have been one of the most significant and widely used tools for fluid control for over 150 years. They are usually used as shut-off devices for they control (primarily stop) the flow of hydraulic liquid with the help of a plate-like barrier.
However, when gate valves go faulty, problems arise as leakages can cause potential damage and give way to the creation of mold which may drastically affect the quality of air as well as the safety situation.
Using the tools, as per the steps mentioned below, you can go about replacing your gate valve with little difficulty.
Step 1: Disassemble the Valve
There are three parts of a gate valve that should be considered while disassembling, namely the stem, the bonnet and the valve body. To go about the replacement, make sure that your water supply is off before you begin.
Once that is done, remove the nut and hand wheel from the stem using screwdrivers, after which move towards removing the packing nut, gland spring as well as the packing gland from the top surface of the bonnet.
Proceed by removing nuts, lock washers and cap screws present in the valve body and the bonnet. Now that all these attachments have been removed, take out the bonnet, the gasket and the disc riser from the stem. Lastly, unbolt the stem from the bonnet and as of this step, your gate valve is disassembled.
Step 2: Clean the Parts
Once all the attachments and components of the gate valve have been removed, use a cloth with a cleaning solvent or a tubing brush to clean them individually. See to it that you clean them thoroughly so as to assure that no dirt, dust or contaminants remain.
Step 3: Inspect the Components
Careful examination of the components is mandatory in order to locate the problems or issues with them, for example, cracks, scratches, stripped threads, rust or possible corrosion. Once the damaged parts have been located, replace them with new instruments/devices bought from the local hardware store and also replace the sealing components that had been used previously.
Step 4: Reassemble the Parts
Nail the stem into the bonnet using a hammer and, keeping it tight in this position, fasten the disc riser until it is in line with the end of the stem. Use two alien screws to hold the discs in place. Twirl the riser counterclockwise until the top of the discs make contact with the end of the bonnet. Now position the gasket on the valve body after which place the lower bonnet as well as the discs onto it.
Proceed by fitting the cap screws, lock washers and nuts in valve body and the bonnet (in a cross fashion) which should be followed by sliding the packing, packing gland and gland spring over the stem and into the bonnet. Now gently slide in the packing nut over the stem and tighten it to the top of the bonnet. Finally, position the hand wheel on the stem and secure its position with a nut.