WPC valve

Water supply system in the working chair is dangerous if the measures are not enough, this information was brought by my relative engineer belongs to the company. So I have made up my mind to replace the water pressure control valve in #4 working chair today. Water over-flow in the working place must cause miserable scenery? Let's make haste!
All the replacement parts are prepared already from the beginning, only my lazy temperament has been preventing me from the measure!