What size pipe for underground sprinkler?
The bigger the pipe the farther you can carry water. Increasing size will not increase gpm or pressure. You can only get what your source will provide unless using a booster pump. A rule of thumb that incorporates pipe size is to choose liquid lines to handle a velocity of 1. This gives 1. Pa/100 m pressure drop.Choose a suitable water velocity based on material, pressure, and application (typically 3-8 feet per second). Use the formula: Flow Rate (GPM) = Pipe Area (square inches) x Velocity (ft/sec). Calculate the pipe diameter based on the desired flow rate and chosen velocity.
What is the 18 inch rule for sprinklers?
The purpose of the “18-inch rule” is to prevent storage or any other obstruction from interfering with the spray of water from a sprinkler head during a fire. It is intended to prevent a situation in which the obstruction is within 18-inches of the ceiling and might be between the sprinkler head and the fire. The max distance between standard spray sprinklers in light hazard settings is 15 ft. The small room rule allows sprinklers to be placed up to 9 ft.A common rule that is followed for obstructions within 18 inches of the sprinkler deflector is the “three times rule”. This requires sprinklers to be positioned away from obstructions a minimum or three times the maximum dimension of the obstruction.