PIPING HYDROTEST PROCEDUREHydrotest adalah pekerjaan yang dilakukan dengan cara memberi tekanan/ pressurepada rangkaian pipa yang sudah selesai dikerjakan oleh team konstruksi. Tujuan daripekerjaan ini adalah untuk mengecek/ test material yang dipakai maupun hasil daripengelasan apakah masih tahan terhadap tekanan sesuai dengan tekanan sewaktuoperasinal nantinya. Sebelum pekerjaan hydrotest terlebih dahulu dilakukan flushinguntuk membersihkan bagian dalam rangkaian pipa dari kotoran, debu dan sisa2las2an hasil pekerjaan pengelasan.

Hydrotest Photo

Hydrotest Chart

Sample Hydrotest Schematic

Berikut ini adalah inti dari procedure/ tata cara (selain daftar isi, referensidokumen, safety, daftar peralatan, dan lain2) kerja untuk pekerjaan hydrotest :

HYDRO TESTING1.

1.1 Hydro test preparationReady for inspection (RFI) notification shall be informed by constructionsupervisor to quality assurance/quality control (QA/QC) department when apiping system is ready for testing. Verification of all materials, test and mill

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piping system is ready for testing. Verification of all materials, test and millcertificates etc. are compiled and documented by QA/QC department andtraceable for each component, fitting and pipe applied to each spool or linenumber. All required non-destructive examination (NDE) results shall beverified to conform to Company general specifications prior performhydrotest.

The contractor’s QC inspector and Company representative shall togethercheck visually in detail for the piping network prior to test. The checkingshall include of:

· Compliance with drawing and battery limit of related subsystem· Welded or flanged joints· Secure and correct bolting· Pipe routing and slope· Location of vent and/or drains· Pipe support, permanent and/or temporary· Temporary spading or blinding· Pipe painting and color coding

The piping supervisor will be responsible for conducting preparation andexecution of pressure test and shall take coordination with QC inspector.Additional material for close the spools such as blind flange shall beavailable on test site and tighten properly prior hydro test (check correctrating).

Pressure gauges and recorder shall be in Bar or Psi unit. Temperatureindicator shall be in degree Celcius. Full gauge range (indicated span) ofpressure test gauges are to be selected in such a way that the test pressurewill be in between 50% to 80% of the full range. A minimum of 2 (two)pressure gauges shall be required for the test. The gauges shall be installedat predetermined locations with one at the highest elevation point and oneat the lowest elevation point wherever possible.

A certified pressure/temperature recorder (maximum validity of pressureequipment calibration 6 months) with full range in steps shall be used torecord the test pressure, temperature and duration of testing. All relevantdetails are to be entered in onto the chart. Recorded to be used shall be ofdual pen. All gauges and recorder shall be calibrated prior to utilization fortest. Any indicator showing an unrecoverable zero error or error more thanplus or minus 1.0% of full scale range shall not be used without repair andre-calibration. One temperature indicator recorder shall be provided.

1.2. Hydrotest ExecutionTest manifold shall be assembled onto the piping network for connection topressure gauges and recorder. Temperature indicator and pressure sourceconnection. Sufficient valves shall be provided to allow blocking or releasingpressure.

For hydrostatic test, the pressure is applied by means of a suitable testpump (hydrotest pump shall be equipped with PSV as safety devices if usedduring pressure test) and gradually built up to 35% of the test pressure andheld for at least 15 minutes to uniform stress along the piping network.Pressure then shall be applied until 70% of test pressure and, again, held for15 minutes. Thereafter, once the required pressure reaches (1.5 designpressure) test pressure, piping network shall be isolated from the pressuresource.

The test pressure shall be maintained 2 hours for holding time as per Companyspecification However this holding time can be prolonged to allow sufficient timefor inspection. QC Inspector and Company representative shall carry out a

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detailed inspection of weld joints and connections for any leak, attention shallalso be paid for dislocation or movement of the supports or distortion.

In case of pressure test is performed in the sunny day, the pressure gauge andtemperature indicator shall be monitored to prevent undue pressure increasedue to thermal expansion In order to avoid excessive pressure the system maybe depressurized down to the required test pressure.

1.3 Limit of Test PressureHydrotest pressure shall be 1.5 times of design pressure and hydrotestpressure shall be indicated in the drawing, lower limit of the test pressure shallbe not less than test pressure specified. Upper limit is 5% of the test pressure,if during hydrostatic test the test pressure increased by more than the upperlimit, the test pressure shall be released or bleed off to the specified testpressure.

If during hydrostatic test the test pressure is decreased to a pressure lowerthan the specified test pressure and there is no evidence of leakage, the lineshall be pressurized back to reach the specified test pressure and held for 2(two) hours

1.4 Inspection During HydrotestUpon reaching the desired holding time, the test pressure shall be reducedto a pressure not less than the test pressure by QC Inspector and theCompany representative shall be carry out visual examination at thispressure. Examination for leakage shall be performed by QC Inspector at allwelding joints and connections

Leakage is not allowed at time of the required visual inspection, except forleakage that might occur at temporary test closures for those openings intendedfor welded connections and leakage from temporary seals (gaskets). Leakageand damages found during the test shall be repaired and rectified. And retestshall be performed.

1.5 Pressure ReleaseAfter the pressure test, pressure shall be released at a rate so as not toendanger personnel or to damage equipment by drawing test medium off theline. Pressure released slowly until the pressure drop to 70% then holding for15 minutes, release again until pressure drop to 35% then holding for 15minutes. Pressure released again until gauge shown 0 bar, all vent shall beopened before the system is drained and shall remain open during drainingprevent pulling vacuum on the system.

1.6 RecordPressure test chart shall be signed by authorized persons. The followinginformation shall be added on to the chart:

· Pressure & temperature ranges· date of test· identification of piping system tested (line and/or spool number)· weather condition· test pressure· test medium· result of testing· names and signatures of executor or supervisor, QC inspector and

Company representativeThe record and pressure chart will be included in the pre commissioningdossier.

POST HYDROTEST DRYING2.

Upon completion of hydrostatic testing, CONTRACTOR shall dewater thepipeline. Contractor shall begin the drying operation only after all testingactivities are complete and accepted by Company. Water shall be moved aheador disposed of after depressurized. Blowing some dry air inside the pipe spool toensure that inside pipe is completely drained. Close the spool with properclosure before continue to other process, which is painting or installation.

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