Jash Engineering Ltd. Manufactures F.R.P. Weir Gates. Jash Engineering Ltd. Is an ISO 9001 manufacturer of Water & Sewage Control Gates, Shut Off Valves for Bulk Solids and Cast Iron T-Slotted Plates. The F.R.P. Weir Gates are downward opening type gates. These are used in decanting of a reservoir or a tank, maintaining precise level control in a reservoir or a tank and controlling the flow into or from a conduit as a sluice gate. These feature flat back frame design offering direct mounting on face of wall. These are made of corrosion resistant material and are light in weight. These can be easily installed.