HOW TO PROCEED FOR HOW TO PROCEED FOR

A HOT TAPA HOT TAP

M. Rasheed KhanM. Rasheed KhanSr. Mechanical Inspector Sr. Mechanical Inspector

E/W Pipelines Project Inspection GroupE/W Pipelines Project Inspection Group

Definitions:

Hot tap

Hot tapping is a technique, performed using specialized equipment for cutting a hole in a pipe, vessel or tank through a welded or bolted branch connection while they are under pressure.

Lock-o-Ring Flange and Plug :

This is a special flange and plug assembly that enables the recovery of the hot tap valve while the pipeline is under pressure. The L-o-R plug has an o-ring seal on its circumference and can be lowered into the bore of the L-o-R flange, using a hot tap machine.

Stopple Split Tee :

A stopple split tee is a specialized fitting with dimensional requirements to suit the stopple plugging head. A regular full sized split tee will not be acceptable for stoppling.

Sandwich Valve:

A special gate valve with a short face to face dimension used as a temporary valve for stoppling. They are also used for hot tapping when the connection will only be used temporarily or when the reach of the hot tap machine is insufficient to complete a hot tap through a conventional valve. These valves cannot be operated unless the pressure is equalized across the gate.

Sandwich Valve

Lock-o-Ring Flange and Plug Stopple Split Tee

Step -1 Step -1 The initiating organization shall prepare a The initiating organization shall prepare a

design package for each hot tap that will design package for each hot tap that will include fully dimensioned drawings, a include fully dimensioned drawings, a materials list, and welding procedures.materials list, and welding procedures.

Step -2Step -2 Inspect and determine the minimum pipe Inspect and determine the minimum pipe

wall thickness at the tie-in weld areas by a wall thickness at the tie-in weld areas by a continuous UT scan along the lines to be continuous UT scan along the lines to be welded and record this on the applicable welded and record this on the applicable form in Appendix A.1 of SAEP-311form in Appendix A.1 of SAEP-311

Note: The UT readings are valid for 30 days. If the field installation is

not completed during this period, responsible engineer shall request inspection to take another set of readings. The responsible operation engineer shall revise the calculations if

the UT readings have changed.

Step -3Step -3 The Responsible Engineer (SAPMT) shall The Responsible Engineer (SAPMT) shall

prepare a separate prepare a separate Form SA 7627-ENGForm SA 7627-ENG for each hot tap operation.for each hot tap operation.

Step -4Step -4 Form SA 7627-ENG has four sections and shall be completed as Form SA 7627-ENG has four sections and shall be completed as

givengiven Section # 1Section # 1 Responsible EngineerResponsible Engineer

Section # 2Section # 2 Operations EngineerOperations Engineer

Section # 3Section # 3 Responsible InspectionResponsible Inspection Unit Unit (operational inspection for UT)(operational inspection for UT)

Section # 4Section # 4 Operations or Project EngineerOperations or Project Engineer

STEP # 5STEP # 5 Prepare the hot tap package which shall include the following;Prepare the hot tap package which shall include the following; Completed form 7627-ENG, "Hot Tap / Stopple and Completed form 7627-ENG, "Hot Tap / Stopple and

Reinforcement Calculation Request"Reinforcement Calculation Request" completed Form 7235-ENG, “Hot Tap Data And Checklist”completed Form 7235-ENG, “Hot Tap Data And Checklist” UT scan thickness measurement UT scan thickness measurement Material take off list for the hot tap Material take off list for the hot tap Welding procedure specification (WPS)Welding procedure specification (WPS) Hydro test procedure Hydro test procedure AB-036719AB-036719 standard drawing for reinforcement of welded branch standard drawing for reinforcement of welded branch

connection.connection. Saudi Aramco Project drawings, P&IDsSaudi Aramco Project drawings, P&IDs

Step # 6Step # 6Contractor shall do the following;Contractor shall do the following;1.1. Site preparation Site preparation 2.2. Split tee mobilization Split tee mobilization 3.3. Split tee installation Split tee installation 4.4. Welding of Split tee Welding of Split tee 5.5. Testing of the welds, MPI or dye penetration Testing of the welds, MPI or dye penetration 6.6. Hydrostatic test of the split with valve Hydrostatic test of the split with valve

Welding of split tee Welding of split tee

Prepare for hydrostatic test after installation gate valve.

Step # 7 Step # 7 After completing the hydro test of hot After completing the hydro test of hot

top fitting together with valve the Form top fitting together with valve the Form 7235: HOT TAP DATA AND 7235: HOT TAP DATA AND CHECKLISTCHECKLIST shall be filled and signed by operation inspection unit.Now it is ready to schedule the hot tap drilling.

Step # 8Step # 8

After installation of the hot tap machine, a final leak test of the entire assembly shall be made with the hot tap valve in the open position by applying pressure through the branch connection boss. The test pressure shall be the lower of the expected line pressure during hot tapping plus 10% or the test pressure as calculated in 13.9, 13. 10 or 13.11 as appropriate. SAEP-311 Para 13.9.1

After completion of the above tests, a bar stock plug shall be installed in the branch connection boss and seal welded. At the option of the Inspector, an MT or PT test may be applied to the branch connection seal weld.

For detail please refer the Saudi Aramco For detail please refer the Saudi Aramco

Engineering Procedure SAEP-Engineering Procedure SAEP-311311

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