Steel flange The steel flanges for stub end must be manufactured and jointed according UNI-EN 1092. Steel flanges shall be supplied with all connecting components: bolts, nuts, washers, gasket. The shape, dimensions and sizes of all the flanges shall be as shown on drawings. Special flanged HDPE T-piece The special flanged T-piece will be used to construct hydrants as is indicated in drawings. The connection to the HDPE pipeline is by but welding. Material will be HDPE 100. The flanged branch of T-piece will be of in diameter and will be used for connection to the flanged hydrant riser of in diameter. The flange material shall be of HDPE 100 or Steel. Special flanged pipes The flanged steel pipes must be manufactured in according clause 5.2.2.2 of General TS. Pipes shall be welded to steel flat flanges, according UNI-EN 15614-1. Double flanged pipes for hydrant risers The flanged steel pipes must be manufactured in according clause 5.2.2.2 of General TS. Pipes shall be welded to steel flat flanges, according UNI-EN 15614-1. The diameter of pipe will be of . Flanges will be attached by welding to both end of the pipe. The length of riser shall be at least above the ground level. On top of the hydrant riser the hydrant valve and a signaling rod will be installed as indicated on the drawings. Drawings, Method of manufacturing and Connection to the underground pipes shall be approved by the Engineer before ordering. Special hydrant valve The hydrant valves will be of or in diameter as indicated on drawings. Material can be of HDPE 100 or steel or aluminum. The hydrant valve shall be approved by the Engineer before ordering. Sample of hydrant valves and connection to the irrigation equipment shall be submitted to the Engineer, for approval. The special hydrant valve will be installed on top of hydrant risers and will be used for connecting irrigation equipment. The irrigation equipment will be provided by water users. The irrigation equipment will be provided with adequate valve connection and will allow opening the hydrant valves. The hydrant valve shall be of NP 10 and will be provided with adequate gasket to provide water tightness while in close position. Hydrant
Valves - general EN Standards have generally been referred to in this Specification. Any other equivalent national or International standard` may be used, subject to the Engineer's approval. All valves shall be best waterworks quality and shall be suitable for use with water or waterworks sludge at temperatures of up to 45o C. Valve bodies shall give the following information: manufacturer's name hydraulic test pressure size of valve direction of flow ‘arrow’ (where flow in only one direction is permitted). The operating gear of valves shall be such that one person can open and close the valve against an unbalanced head 15% in excess of the maximum likely to be encountered in service. Gate valves be provided with renewable seats. Gates shall be capable of being removed without removing the valve body from the pipework. All valves shall have a pressure rating as designated on the drawings, the rating of a particular valve being equal to or greater than the maximum working pressure (including surge) to which the valve may be subject under pipeline operational conditions. The operation of all valves shall be such that they are closed by turning the handwheel or in a clockwise direction. The handweel or tee-key shall be large enough to allow operation by one person. All materials shall comply with the appropriate EN Standards and shall be subject to the Engineer's approval. All castings shall be free of blowholes and other defects. All standard valves shall be suitable for frequent operation, and for infrequent operation after long periods in the open or closed condition, and shall satisfy the requirements of the open and closed end tests. Butterfly valves be installed in the pipework in such a manner that they can easily be removed from the line for dismantling and replacement of the seats and seals, and shall be designed to give minimum leakage. Check (non-return or reflux) valves shall possess high speed closing characteristics, with minimum shock on closing. (a) Gate valves