PLUMBING WORKS IN BUILDINGS - METHODLOGY

 A. INTERNAL WORKS - Water Lines

1.            Internal pipe work in Toilets and Kitchen to be concealed and carried out as per working drawings.

2.            As per the heights mentioned in plumbing drawings, mark the line on walls by chalk in proper alignment and plumb

3.            Start chasing of line using a chasing machine or chisel and hammer. The chasing should be done keeping the following points in mind.

Ø            Depth -                 Should not be more than pipe size

Ø            Width    -              Sufficient to accommodate the pipe line

Ø            Alignment -         Straightness should be considered

Ø            Height   -              For all fittings height as given in Drawing

5.            Check Class / Specifications of Materials.

Ø            High Pressure threaded Blue UPVC Pipes of Schedule 80 to be used for cold water pipes made of ASTM IS-1785 and threaded as per IS 1239 (Part I)

Ø            Class 1 Copper pipes as per BS 2871 Part 1 and fittings as BS 864 Part II should be used for Hot Water.

Ø            G.I Fittings should be used for cold water – pipe work as per IS 1239 (Part II)

6.            Prepare pipe-skeleton and check all joints for proper tightness. Only approved make pipes, pipe fittings and accessories including jointing materials should be used

7.            Groove chasing should not exceed 30 mm after rough plaster for cold water supply line and cold feed line and 50 mm for hot water supply lines.

8.            While threading UPVC pipe at site, ensure square cut of pipe ends, chamfer the ends with a file, insert proper size wooden plug in the pipe end and then carryout threading. The sharp edges of gripping vice and other handling tools should be muffed with a suitable packing to prevent damage of pipe surface.

9.            The joints should be made with hand tightening of the fitting over pipe and covered with proper layer of Teflon tape. To make the joint permanent, one to two turns over the hand tightened joint is sufficient. Avoid over tightening as this may damage both the pipe and fittings.

10.         Special care should be taken while connecting UPVC pipe with G.I Fittings. High quality shellac should be used for jointing.

11.         Water tightness of line to be checked using pressure testing equipment. All other openings should be plugged except end portions to which pressure gauge machine is connected.

12.         The pressure reading should be above 7 kg/cm2 (80 PSI); and there should not be even a single drop of water coming out of the joints during testing. The duration of the test is 24 hours.

13.         Apply bitumen paint over the G.I pipe work.

14.         All the bore pieces projecting out should be minimum 200 mm from plastered surface.

15.         Cover the skeleton including fittings with good quality Hessian cloth and tie it properly for cold water pipe work.

16.         Fix the skeleton in wall using 40 mm plumbing nails at a distance of 230 mm on alternate side.

17.         Do the pressure testing once more after fixing in position and ensure no leakage.

18.         Keep a gap of 10 mm between all pipes and fittings to accommodate thermal expansion and contraction of pipes for longer life of the system.

19.         Horizontal lines within bathrooms should be cement encased and tested before compacting of sunken floor to avoid any accidental damages.

20.         Curing should be done over the plaster for at least 7 days.

Installation Guide For Copper Pipes (Hot Water Lines)

1.            Make sure that you have the correct size fittings and tube.

2.            Prepare the end of the tube by cutting to the correct length with a tube cutter or fine bladed hacksaw. The ends of the tube must be cut square to the axis and be especially careful not to damage the ends of the tube. After cutting the tube, you will notice some rough edges around the outside and inside of the tube. This is called burr and should be removed with a file or sharp blade.

3.            Clean the outside surface of the tube that will eventually go into the socket of the fitting, along with the inside surface of the fitting. 

4.            Apply water soluble flux to the tube and fitting by smearing a thin film of FLOWFLEX Flux around the outer ends of the tube that have been cleaned and to the inside of the cleaned socket of the fitting. This is best done with a small brush to avoid applying too much and to prevent contact with the skin. 

5.            Insert the tube into the fitting and push home until the stop is reached and wipe off any excess flux with a clean cloth.

v            For Integral Solder Ring Fittings (Inbuilt):

6.            Apply heat to the assemble joints to be made using a conventional blow Lamp torch or similar appliance that emits flame that is clean, blue and soot-free. Once a complete ring of solder has appeared around the mouth of the fitting, turn off the heat. The complete silver coloured ring of solder is proof of a sound joint.

v            For End feed Fittings:

7.            Apply the flame to the fitting to heat tube and solder cup of fitting until solder melts when placed at the joint of tube and fitting. Allow the joint to cool without disturbance. 

8.            Remove the flame and feed solder into the joint at one or two points until a ring of solder appears at the end of the fitting. The correct amount of solder is approximately equal to 1 ½ the diameter of the fitting ¾” long solder for 15mm fitting etc. 

9.            Wipe off any excess flux and residues, with wiping cloth after the joints cooled

B. INTERNAL WORKS - UPVC TRAPS

INSTALLATION:

1.            Determine correct location of ‘P’/ ’Q’/ ‘S’ Traps and set it on a firm base located relative to the floor finish by pouring concrete on a slab.   

2.            Bedding can be carried out by pouring concrete around ‘P’/ ’Q’/ ‘S’ Trap; ensuring that outlet of Trap is left clear on concrete.

3.            Apply rubber lubricant on W.C. connector ring as well as on outer side of WC pan 

4.            The outlet can be inserted in the socket end of pipe / fittings (as the case may be) and joint can be solvent cemented to make a leak proof joint. 

JOINTING INSTRUCTIONS

1.            Make sure the spigot end and inside of the socket is clean and the sealing ring is placed evenly in the socket. 

2.            When cutting pipes, make sure they are cut square. Chamfer the end cut to an angle of 15 0 with a medium file. Cutting of pipes should be straight, as diagonal cutting leads to leakages

3.            A correct depth of entry of the spigot into the socket is required to allow thermal movement. To achieve this, push spigot fully into the socket (remove sealing ring at this time) and make a mark on the spigot. Withdraw the spigot by 10 mm & mark the spigot with the bold line. This bold mark indicates the correct depth of entry to allow the necessary expansion gap.

4.            Smear rubber lubricant evenly on the chamfered spigot and the sealing ring. Then insert the spigot into socket with light twisting motion. Pull out the pipe to allow 10 mm expansion gap.

5.            Maximum Support Distance In Meter:

C. EXTERNAL PIPE WORK

1.            Spacing of inspection chambers and manholes should be such that cleaning of sewer lines can be done easily.

2.            Inlets and outlets of chambers and manholes are to be plugged during progress of the work. It should remain plugged till completion of the sewer lines up to disposal so as to avoid blockage / choke-up of sewer pipeline.

3.            Ensure gully’s/channels of inspection chambers/manholes have given a smooth curve if sewer lines are intersecting at right angles.

4.            Bottom of gully’s/channels should be laid in slope at inlet to outlet of chambers and should be finished smooth.

5.            All sewer pipes, traps and other fittings should be free from cracks, holes and burrs etc., and to be checked before being put into use.

6.            Outflow of chamber should have 25 mm (1”) drop than in flow of chamber.

7.            Joints of sewer pipes to be plugged with cotton yarn (packing rassi) before applying cement slurry over joints.

8.            Heavy-duty chamber covers are to be used in parking and on road whereas light duty covers may be used for other places. The covers used in manholes in sewer lines shall invariably bear the word, ‘SEWER’ on the top and those used for storm water drains shall bear the word ‘STORM’.

D. SOIL WASTE & RAIN WATER (S.W.R) DRAINAGE SYSTEM

JOINING INSTRUCTIONS:

1.            Use only rubber lubricant for joining SWR pipes & fittings, where rubber ring is used. 

2.            Avoid misalignment of vertical SWR pipe stacks and incorrect spacing of pipe clips.

3.            All entry to main stacks should be protected with water seal trap, wherever there is mixing of soil & waste lines.

4.            Keep a gap of 10 mm between all UV stabilized SWR pipes and fittings to accommodate thermal expansion and contraction of pipes for longer life of the system.

5.             Smoke test should be avoided and test plug / socket plug should be used for testing the lines.

6.            Horizontal lines within bathrooms should be cement encased and tested before compacting of sunken floors to avoid any accidental damages.

7.            When cutting pipes make sure they are cut square. Chamfer the end cut to an angle of 150 with a medium file.

8.            A correct depth of entry of the spigot into the socket is required to allow the thermal movement. To achieve this, push spigot fully into the socket (remove sealing ring at this time) and make a mark on the spigot. Withdraw the spigot by 10 mm & mark the spigot with a bold line. This bold mark indicates the correct depth of entry to allow the necessary expansion gap.

9.            Smear rubber lubricant evenly on the chamfered spigot and the sealing ring. Then insert the spigot into socket with light twisting motion. Pull out the pipe to allow 10 mm expansion gap.

10.         Tubes installed underground, laid on floors or in other inaccessible places must be able to withstand twice the maximum working pressure.

11.         While laying big pipelines provision should be made for expansion joints, air vents and proper anchorage. In case of longer runs provide air valves at all higher points of ground and the size of the valves should be ¼th of the main line.

12.         For large diameter and higher class pipes (6 kg / cm2 and above) always use heavy-duty solvent cement. Within 24 hours, the rigid PVC pipes are ready for use.

TESTING NON-PRESSURE INSTALLATION ABOVE GROUND      

The SWR drainage system can be put to use immediately after installation, as no waiting time is required for joints to be set and dried. However for testing, seal hermetically all openings below the top of the section to be tested. The water level shall then be raised to a height of not less than 3 meter above the highest point of the section being tested. Every joint shall be carefully examined for leaks

E. DUCT & HIGH LEVEL PIPEWORK

1.            Pipe work in ducts and voids shall be supported from specially designed mild steel brackets and cantilevers with swinging hangers. Roller type supports and ‘U’ bolt clips shall be used.

2.            The brackets shall be provided and fixed to the sidewalls, beams and ceilings, where a bracket or support carries more than one pipe of different sizes, the spacing of the brackets or supports shall be that specified for the smallest size of pipe.

3.            All pipes must be kept at least 150 mm from lighting and power cables or conduits.

4.            Pipes shall be spaced in ducts and below floors in a manner, which will permit subsequent access to any pipe for maintenance or removal without disturbance to the remaining pipes.

5.            All piping shall be grouped wherever practical and shall be erected to present a neat appearance. Pipes shall be parallel to each other and fixed at right angles to structural members and shall give maximum possible headroom. All pipe drops shall be truly vertical.

6.            All pipes must be supported in such a manner so as to allow free movement for expansion and contraction and graded to the required levels for air elimination and drainage.

F. RETICULATED LPG SYSTEM

1.            The Gas Cylinder bank provided, is equipped with a manifold to which the cylinders are connected. Each point of connection of the cylinder to the manifold has got a Non Return Valve to take care of any emergency arising out of failure of the Cylinder Pigtail.

2.            To take care of excess Pressure build up in the pipeline after the regulator, an Over Pressure Shut Off system coupled with the Regulator is provided.

3.            As far as the pipeline is concerned, there will be no threaded joints in the pipeline. The pipeline would be necessarily DC Socket welded and hydro tested in line with the code requirement.

4.            Moreover, leak detectors may also be installed in the Gas Cylinder bank, which would give an audiovisual indication once the LPG level in the enclosure increases beyond safe limits.

TOOLS TO BE USED BY TRADESMEN

Required tools must be available at site to ensure correct work. Basic tools of the plumbing gang are:

1.            Chisel

2.            Pipe Wrench

3.            Chain Wrench

4.            Sledge Hammer

5.            Screw Driver

6.            Bench Vice 

7.            Pipe Vice

8.            Die Set

9.            Hammer Drilling M/C

10.         Mini Angle Grinding M/C

11.         Drill

12.         Chasing Machine

13.         Spirit Level

14.         Hammer Drill Bit

15.         Grinding Wheel

16.         File

17.         Measuring Tape

18.         Pressure Testing Machine

  INSPECTION METHODOLOGY FOR QUALITY ASSURANCE

1.            Check the direction of flow vis-à-vis the installation of pipes

2.            The water has to flow into the sleeve. Check for leakage and subsequently establish whether due to faculty sealing [Insufficient application of adhesive]

3.            Check for slopes installed using spirit levels

4.            Ensure all joints are waterproofed to ensure leak proof pipes  

TOOLS TO BE USED FOR QUALITY INSPECTION

1.            Spirit levels

2.            Plumb bob

3.            Measuring tape

4.            Related “Good for Construction” service drawings