Texas Administrative Code|§3.24 Check Valves Required

                                                
(a) Where two or more wells are being produced through a common line, a common separator, or a common manifold, the flow lines leading from each well to such common line, common separator, or common manifold shall be equipped with a check valve or other means of shut-off which shall at all times be kept in good working order. The check valve or other means of shut-off shall be placed in each flow line above the surface of the ground and shall be located in the flow line as close to the wellhead connection as is practicable. Where a manifold system is employed in which each well produced through the manifold system has its own individual flow line leading from the wellhead to the manifold, then it shall be permissible for the check valve or other means of shut-off to be placed in the flow line near a point where the flow line enters the manifold system. The check valve or other means of shut-off must be above ground, and must be in the flow line serving the well and must be located between the wellhead and the point where the flow line connects with any other flow line, common separator, or common manifold. Each check valve or other means of shut-off shall be placed in the flow line serving the well so that it will permit the passage of fluids from the well and will act as a check to prevent any fluid from entering the well through the flow line from any outside source. (b) Operator shall do all things necessary to keep the check valve or other means of shut-off in good working order, and operators, when requested by an agent of the commission, will test the check valve or other means of shut-off for leakage.