Copper Pipe Brazing | Copper Pipe Joints

On this page you shall find a brief method statement for copper pipe joints installation and brazing for any kind of project.

Below is list of mandatory tools and equipment’s that are useful for this activity.

Tool box for Mechanical/Hand Tools
Leveling Instrument
Silver Brazing Rods
Blow-Torch or Heating Torch
Thermometer (Heating gauge indicator if any)
Grinding Machine, Drilling machine & Cutting Machine
Oxygen & Acetylene cylinder & Cutting outfit
Measuring Equipment’s
Applicable PPE & Welders Safety equipment’s.

PRE-INSTALLATION PROCEDURE

All workers to attend safety induction conducted by main contractor and given specific training on the safe installation methods.

Task lighting to be ensured prior to start of copper pipe brazing including the work of riser piping.

Riser checklists to be filled and kept updated till completion of riser pipes brazing activities.

Copper pipe brazing jointing works shall be done as indicated on the approved shop drawings and as per site requirements.

The Site Engineer, Site Supervisor will give necessary instructions to certified welders and tradesmen, also to provide necessary approved construction/shop drawings of latest revision along with coordinated layouts.

Site engineer and supervisor shall also explain to the certified welders and tradesmen regarding necessary safety precautions as per risk assessment and project HSE plan.

INSPECTION GUIDANCE FOR BRAZING WORKS

Site engineer / supervisor will complete the inspection checklist and follow the inspection & test Plan detailed in this procedure.

The intent of this procedure is to establish a high level of assurance that the end product meets the specification requirements and consultant satisfaction.

QA/QC inspector shall verify that the approved procedures for brazing are followed and the inspections and testing records are completed.

Copper pipe joints / Copper pipe brazing

Prior to alignment of pipes for brazing each length of pipe will be inspected thoroughly to ensure that no visible defects are present.

Check the materials as per the material submittals, standards and specifications and get approval from the consultant/ Employer representative.

The ends of each pipe and the area which is adjacent (at least 1″ from the edge inside and outside) shall be thoroughly cleaned from the rust, paint oil scale or the other foreign materials, which are harmful for welding and brazing alloy heat build up quality.

Each length of pipe shall be thoroughly cleaned by blowing air from both ends of the pipe.

Protect and cover the openings of pipes with suitable cap or polyethylene sheet in order to avoid any foreign material entering.

Ensure both pipe ends are clean without any dirt or oil deposits before inserting to the socket which is Endex socket fittings, pressing firmly to reach stopper tip from inside socket, start leveling until it is firm, follow below procedure.

For proper aligning, external pipe clamps or jigs shall be used and (tack welding) or initial application of brazing alloy to hold the alignment.

When above is not possible, tack welding shall be used for alignment.

Ensure all brazing alloy rods are suitable to use particularly for wall thickness of the copper pipe and its diameter size of the copper pipe to ensure proper usage as per manufacturer’s data and recommendations.

Pre heating temperature must be 700 to 750°C (COPPER PIPES).

Heat the assembled joints between pipe and fittings evenly on all sides while heating build up encircling direction either left to right depends on the welder.

Apply solder or brazing alloy rod to the mouth of the fittings, when reaches the correct temperature the solder alloy will flow freely into the joints.

Briefly reapply the blowtorch and wipe off any excess flux residues (solders).

Allow the joint to cool down without disturbances (not flash with water or any Coolant), and clean the joint by fine sand paper generally to remove excess flux residues.

BRAZING / WELDING CONFORMANCE

Welding / Brazing alloy of piping shall be performed in accordance with the approved WPS based on project specifications and applicable codes for BS standards; hence there is no welding or brazing procedure specification on the project mentioned.

Brazing contractors’ ability and expertise will be incorporated on this method statement based on welding code standards and according to manufacturer’s recommendations and as per client agreement.

Oxy-acetylene welding to BS 26340 Class 11 with filler rods to BS 1453 and BS EN 12536 as appropriate. Arc welding to BS 4515 and BS 2971 Class 11.

Bronze welding of copper tube & pipes shall be oxy-acetylene and inert gas shall be in accordance with BS 1724.

Flange connection shall be according to ANSI standard, or otherwise as stated and agreed by client/consultant.

Contractor shall provide all relevant certificates if required by client/consultant.

Welding shall not be permitted when weather conditions are bad viz. rain, high winds or any other climate condition that may hamper the quality of welding.

Proper wind protection closures shall be provided for welders during welding.

All the equipment used for welding & brazing shall be in good condition.

Raise work inspection request (WIR) to consultant, all fabrication shall be visually inspected and acceptance criteria shall be as per the inspection and test plan ITP.

All welds and brazing joints will be 100% visually examined, conformity to drawing shall be done for all the lines checking that all components supports, brackets, etc. are installed as per approved materials and shop drawing details and specifications of the project.

Brazing Procedure Using Oxy Acetylene Brazing Set

The purpose of this document is to establish a standard maintenance procedure for the proper usage of brazing set and to familiarize technician how to conduct brazing using Oxy-Acetylene Brazing Set.

Scope of this standard method covers all equipments which require the use of brazing set for the repair and installation of refrigeration and air-conditioning equipments including the copper pipes/tubes.

It is the responsibility of the maintenance technician to operate and check the condition of the brazing set. He should be competent enough to use this equipment since it is extremely dangerous when not used properly. The supervisor and the site engineer should assure that this maintenance procedure will be followed.

Brief Description of Oxy-acetylene Brazing Set

Oxy-acetylene brazing process uses a high temperature flame. Oxygen is mixed with acetylene gas to produce the high heat.

Brazing equipment includes: oxygen and acetylene cylinders, pressure regulators, hoses, fittings, safety valves, torches and tips.

The regulator has two gauges, one to register tank pressure and the other to register pressure to the torch.

Red hose is attached to the acetylene regulator with left-handed threads and the green hose to the oxygen regulator with right-handed threads.

Brief Description of Oxy-acetylene Brazing Set

Setting-up Oxy-Acetylene Equipment

Prior to the work, wear safety shoes, safety glasses and gloves. It is advice also to place a Fire Extinguisher near the site during brazing.

Prepare t oxy-acetylene brazing set, adjustable wrench, brazing rod, copper tube, tube cutter, reamer, fittings, sand cloth and brush.

Crack the cylinder valves to blow any foreign matter which may damage the seats or block the orifice.
Connect the regulator to the cylinder and tighten the nut securely with a wrench.
Connect the hose assembly to the regulator and handle.
Connect the correct size tip to the handle. Use the tank key and leave it on the tank.
Set-up the adjusting screw for the appropriate pressure.
Light the flame using flint lighter. Make sure that the pointing tip is not pointing at flammable object or person before igniting.
Adjust pressure valves to get the desired flame. Characteristics of a Flame:
- Neutral Flame – burns equal amount of oxygen and gas and is Used in welding steel, stainless steel, cast iron, copper and aluminum.
- Oxidizing Flame is achieved by burning excessive amount of oxygen. The center blue cone has a distinct point and achieved by setting a neutral flame then reducing the amount of acetylene. This flame is used when welding brass.
- Carburizing or reducing flame is obtained by opening the acetylene further than required for neutral flame.
To shut-off the torch, close the oxygen valve in the blowpipe first then the acetylene valve.
Close the tank valve and open the blow pipe valves to allow the gas to drain out from the hose.

Procedure for Brazing Jointing the Copper Tube / Pipe

Prior to the work, wear safety shoes, safety glasses and gloves. It is advice also to place a Fire Extinguisher near the site during brazing.

Cut desired length of the pipe and remove the burrs using a reamer.

Clean mating parts of the joint. Clean the tube and fitting with sand cloth and then with a brush.

Apply a flux to the male connection.

Assemble the tubing and fitting and place it in a support to avoid moving while brazing.

Start heating the tube near the fitting for a short time.

Move the torch from the tubing to the fitting.

Keep moving the torch to spread the heat evenly and do not overheat any area.

Hold the torch so that the inner cone of the flame just touches the metal.

After briefly heating the joint, touch the brazing rod to the joint.

(Do not melt the rod with the flame, the rod should melt and flow freely from the heat of the metal.

Feed enough brazing rod to fill the joint.

For horizontal joints, it is preferable to apply the filler metal first at the bottom, then to the sides and finally to the top, making sure the operations overlap.

When the joint is at the correct temperature, it will be cherry red in color.