Method Statement: Testing Dry Riser System

Transcription

1 Method Statement: Testing Dry Riser System Page 1 of 6 Scope of work Test dry riser system in accordance with BS Definitions For the purposes of this document, the following definitions apply Rising Mains A vertical pipe installed in a building for the fire fighting purposes, fitted with inlet connections at Ground Level, and outlet valves at specified points, which is normally dry but capable of being charged with water, usually by pumping from a Fire Service appliance. Landing Valve An assembly comprising a valve and outlet connection from a wet or dry riser. Inlet Breeching An assembly comprising inlet connections and a drain valve, normally fitted within an inlet box. Air Release Valve The valve fitted at the highest point of the dry riser to provide automatic bleeding of air from the system when it is filled with water. Low Level Drain Valve The valve fitted at the lowest point of the dry riser in cases where parts of the system are installed below the inlet breeching. Competent Person A competent person is one who has practical and theoretical knowledge, and actual experience of the type of equipment which the person has to examine, as will enable the person to detect defects or weaknesses and to assess their importance to the proper functioning of the equip ment. General All tests are carried out using pressurised water. It is considered dangerous to test a dry rising main using compressed air. All personnel involved in testing should maintain effective contact (e.g. by radio) with the pump operator at all times so that the pump can be shut down in the event of a failure. It is important to ensure that all landing valves are closed and secured before commencing work.

2 Page 2 of 6 It is important to ensure the adequate drainage is available when carrying out the flow test and when draining the dry riser. Test Procedure Check the inlet box (if fitted) door and hinges are undamaged and the locking arrangement works satisfactorily. Inlet boxes (if fitted) should be secured by a night latch type lock if the door is glazed or by a light padlock if the door is solid. The position of the inlet (if fitted within a box) should be clearly indicated using the appropriate sign in accordance with BS5499: Part 1, using lettering height of 50mm. If a system has any components or pipework below the level of the inlet breeching, a sign indicating the location of the lowlevel drain valve should be displayed in the inlet box (if fitted). In addition, a sign should be displayed by the low-level drain valve indicating its purpose. Check the inlet breeching has a drain valve, which operates, and that water will drain to waste without causing damage. Check the non-return valves in the inlet breeching operate and the seals are present and in good condition. If there are outlet boxes, they should be checked as for the inlet boxes. If the landing valves are not in boxes, check they are secured closed with a strap and padlock. When valves are housed in boxes, the position of the outlet valves should be clearly indicated using the appropriate sign in accordance with BS 5499: Part 1, using a letter height of 50mm. Check all landing valves to ensure there is no obvious damage and the handwheel is securely fixed to the stem. Check the featheredge outlet seal is undamaged, then replace or renew as required. Release any padlocks and check the valves operate freely. Leave them locked in the closed position. Check the outlet twist mechanism operates freely and there is room for a standard dividing breeching to be fitted into the valve. Check that ventilated blank caps are fitted.

3 Page 3 of 6 Pressure Test Before carrying out a wet test, check the outlets on all floors are closed, and the breeching drain cock and any low level drain valves are shut. Connect a single line of hose from the pump to the inlet breeching via a pressure release valve. Open the pump delivery and allow the main to fill at engine tick-over pressure. At a pressure of approximately 0.1 bar per metre of height will be needed to fill the main, additional pump assistance may be needed. Allow system to fill air being released through the air release valve, if fitted. Open the roof or highest outlet and allow water to discharge onto the roof until it is clean and free of any debris. Close the roof outlet landing valve. Check the air release valve functions and does not allow any water spillage. Walk down to Ground Floor, checking at each level there are no leaks from the rising pipe or landing valves. At the inlet breeching, check the non-return valve of the inlet not in use is working. Shut off the pump and reconnect the hose to the other inlet. Switch on the pump and check the non-return valve of the first inlet. Having checked there are no major leaks, the system should be pressurised to 10 bar at the inlet and the pressure at the highest outlet with no flow should be recorded. The difference between the inlet and outlet pressure is the static head and will be approximately 0.1 bar per metre of height. Once the system is pressurised, the pump should be turned off and the hose disconnected from the inlet. The static pressure at either inlet or outlet should be observed. Any drop in pressure indicates a leak in the system and a reduction of more than 2 bar within 15 minutes is classified as a failure. In the event of a pressure loss, drain system immediately, check at all levels for leaks to rising mains joints, landing valves, air release valve, inlet breeching and drain valve, and report cause of leak to client. If no pressure loss, the system must be pressurised at 10 bar inlet pressure for at least 15 minutes without mechanical failure.

4 Page 4 of 6 Flow Test Flow tests are carried out only where practical. Connect a short length of hose and an approved and calibrated flow metre to the roof mounted outlet valve (valve in closed position). Run the pump to 10 bar at the inlet, and fully open the roof outlet valve, allowing water to discharge onto the roof. Allow water to discharge for a period of at least 30 seconds. Record flow rate. Close outlet valve, stop pump and disconnect hose. Shut down the pump and open the pressure release valve to release pressure in the hose before disconnecting it from the inlet. Remove any test gauges and drain down the riser via the breeching drain cock. Close the drain valve, refit the blank caps to the inlet breeching. Rectification of Defects Any maintenance and rectification of defects must be carried out by a competent person in accordance with the manufacturer s instructions. Replacement of Parts Only the correct components supplied or specified by the manufacturer of the equipment or equivalent approved parts should be used to replace those found to be unsuitable for continued service. Certificate and Report Upon completion of the test where defects are found furnish client with detailed Test Report and quotation for remedial works. Upon satisfactory completion of the test after remedial works (if any) furnish client with Certificate of Conformity and copy of the Test Report. Working Practice Chase Fire engineers will, at all times, be mindful of the client and the specific requirements of the site.

5 Page 5 of 6 Chase Fire engineers are fully trained on and experienced with dry riser systems, and their associated parts and components. Chase Fire engineers are fully trained on and experienced with the use of all tools, plant and safety equipment to be used to carry out these works. Chase Fire engineers are supplied with all the necessary personal safety equipment, including hard hats, goggles, ear defenders, safety boots, overalls, high visibility jackets etc. Chase Fire engineers are supplied with necessary free standing signs, warning tapes and barriers. Chase Fire engineers each have mobile telephones and two way radios. Chase Fire vehicles will be driven onto site only with the approval of the client, and whilst on site will be driven in a safe manner, fully in compliance with site safety requirements. Chase Fire vehicles will be parked in a safe and appropriate manner, and will display hazard warning lights and flashing beacons when considered appropriate and necessary. Safety Equipment Hard hats, safety boots, full overalls and high visibility waistcoats will be worn as required and necessary. Ear defenders, eye protective goggles, safety gloves, breathing masks and harnesses to be worn as appropriate and necessary, and as required by the client. Safe Working Notify relevant and responsible client representative of area of work at all times. Learn, understand and action specific site emergency procedures note this may vary from area to area within the site. Learn, understand and action specific site requirements of personal protection note this may vary from area to area within the site. Learn, understand and action specific site requirements for working practices, including use of power tools note this may vary from area to area within the site.

6 Page 6 of 6 Work only in accordance with safe practice, and company and client safe procedure. Tools Power tools will be battery operated or 110 volt only. All Chase Fire tools are properly and correctly maintained and tested. Storage Materials and tools will not be stored on site. Debris and Rubbish Chase Fire engineers will clear away all removed and discarded materials, including redundant parts and packaging etc. Chase Fire will keep all areas of work free from debris and rubbish particularly walkways. Clearing up will be completed as debris and rubbish appears. Water Some water spillage is inevitable. Spilled water will be mopped up as it appears. Appropriate signs to warn of slip hazard will be used as and when necessary.