DKB_Hydrotests

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ISO 14692 WorkgroupDubai Meeting 20-22 Apr 2009

Shop and Field Hydrotests

[DRAFT ONLY]

Dennis Kirk-Burnnand



Why Hydrotest?

• To manage the commercial, technical, safety and environmental risk for all

stakeholders

• Stakeholders include manufacturer, designer, installer, operator, owner,

regulator, landowner and the public

• Shop test to ensure that the products being manufactured are suitable forservice (including field hydrotest)

• Field test to ensure that the finished pipe system has been installed

correctly (the only form of NDT) and will not fail or leak in service

• Test at the maximum pressure that the pipe will tolerate safely without

damaging it so that the residual risk is minimised

• Shop test conditions > Field test conditions > Operating conditions



Sqs vs Sthr

• For GRE Sqs = Sthr (threshold stress for micro cracking)

• For GRP the two values may be different

• The design will be based on a long term failure envelope defined by;

• Shl = Min(Sqs, Sthr)• Note: The associated P = Shl x 2 x tr,min / Dm will only produce Shl in a pipe of minimum wall thickness

• Manufacturers pressure rating

• Pmpr = 0.67 x Shl x 2 x tr,min / Dm



ISO 14692 Shop Hydrotest



ISO 14692 Shop Hydrotest• ISO 14692-2 currently requires;

• Pshop = 0.89 x Pq for D up to 600 mm

• Pshop = 0.75 x Pq for D greater than 600 mm

• But the field hydrotest can be at this same pressure and

• API 15HR shop hydrotest is at 1.0 x Pq

• ISO 14692-2 proposed change;

• Pshop = 1.00 x Shl x 2 x tr,min / Dm for D up to 600 mm [or 1.5 x Pmpr]

• Pshop = 0.75 x Shl x 2 x tr,min / Dm for D greater than 600 mm [or 1.1 x Pmpr]• Note that reference to Pq has been replaced

• Note: P = 1.00 x Shl x 2 x tr,min / Dm will only produce Shl in a pipe of minimum wall thickness

• Short term burst testing for batch acceptance is optional and should beconsidered for pipeline materials.



ISO 14692 Batch Acceptance Burst Test

ASTM D1599 Procedure A

ASTM D1599 Procedure BTest Test

Note: ASTM D1599 Procedure B test may be haltedwhen the baseline Psthp is reached or exceeded

Note: Baseline Psthp is a 97.5% lcl value therefore2.5% of the batch acceptance tests will FAIL!!!!!



ISO 14692 Batch Acceptance Burst Test

ASTM D1599 Procedure A

ISO 14692-2 proposed change;

Convert the ASTM D1599Procedure A pressures to hoopstresses using the actual tr,min ofeach test pipe

Determine the 97.5% lcl hoopstress of all tests

Convert the 97.5% lcl hoop stress

to the baseline Psthp using theguaranteed tr,min of the productionpipes

This should be sufficient to ensurethat the initial batch acceptancetest passes

Should the initial test fail then testtwo more samples both of whichmust pass for the batch to beaccepted

Note: Tested pipes must be disposed ofand not returned to the batch.



API 15HR Shop Hydrotest



API 15LR Shop Hydrotest





Documents

DKB_Hydrotests