Time delays, guards

The most economically beneficial time to consider the safeguarding of plant is at the early design stage when the guards can be included at relatively small cost and can be incorporated as an inherent part of the plant (this also makes them more acceptable to the operators). Delaying consideration of the necessary safeguards until the plant is commissioned increases the cost enormously and the guards will always look what they are, add-ons. 

The "valve shut" tag method is used to guard against delayed reopening of valves. "Valve shut" tags should be used every time a sprinkler control valve is closed. When the valve is reopened the 2-inch drain should be flowed wide open to be sure there is no obstruction in the piping. The valve should then be resealed or relocked.)... 

---