A gate valve is the most common shut-off valve used to regulate flow control. This type of valve controls the flow levels of gas, liquids and steam. Disassembly is necessary when you are either replacing a gate valve or repairing it.
Locate and turn off the main water supply before disassembling the gate valve.
Take the screwdriver and remove the nut and the hand wheel from the top of the gate valve.
Unscrew the packing nut from the stem and remove the gland spring along with the packing gland from the top portion of the bonnet.
Remove all the nuts, lock washers and cap screws that are visible on the valve body and bonnet.
Take the bonnet, the gasket and the disc riser off of the stem. Unbolt the stem from the bonnet to complete the process.