ARTICLE NH-6000

NH-6100 General Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65NH-6110 Scope of Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

NH-6111 General Hydrostatic and Pneumatic Test Media. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65NH-6112 Pressure Testing of Components and Appurtenances. . . . . . . . . . . . . . . . . . . . . . . . . . . . 65NH-6113 Pressure Testing of Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65NH-6115 Time of Pressure Test and Stamping of Components and Appurtenances. . . . . . . . . 65NH-6116 Machining of Local Areas After Static Pressure Testing. . . . . . . . . . . . . . . . . . . . . . . . 66NH-6117 Alternative Tests of Closure Welds and Access Hatches. . . . . . . . . . . . . . . . . . . . . . . . 66NH-6118 Alternative Tests at Specially Designed Welded Seals. . . . . . . . . . . . . . . . . . . . . . . . . . 66

NH-6120 Preparation for Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66NH-6121 Exposure of Joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66NH-6122 Addition of Temporary Supports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66NH-6123 Restraint or Isolation of Expansion Joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6124 Isolation of Equipment Not Subjected to Pressure Test. . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6125 Treatment of Flanged Joints Containing Blinds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6126 Precautions Against Test Medium Expansion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

NH-6200 Hydrostatic Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6210 Hydrostatic Testing Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

NH-6211 Provision of Air Vents at High Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6212 Test Medium and Test Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6213 Check of Test Equipment Before Applying Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . 67NH-6215 Examination for Leakage After Application of Pressure. . . . . . . . . . . . . . . . . . . . . . . . . 67

NH-6220 Hydrostatic Test Pressure Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6221 Minimum Required System Hydrostatic Test Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6222 Maximum Permissible Hydrostatic Test Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6223 Hydrostatic Test Pressure for Valves, Pumps, and for Components and

Appurtenances Containing Brazed Joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6224 Hydrostatic Test Pressure Holding Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

NH-6300 Pneumatic Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6310 Pneumatic Testing Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

NH-6311 General Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6312 Test Medium and Test Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6313 Check of Test Equipment Before Applying Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . 68NH-6314 Procedure for Applying Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69NH-6315 Examination for Leakage After Application of Pressure. . . . . . . . . . . . . . . . . . . . . . . . . 69

NH-6320 Pneumatic Test Pressure Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69NH-6321 Minimum Required System Pneumatic Test Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

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NH-6322 Maximum Permissible Pneumatic Test Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69NH-6323 Pneumatic Test Pressure for Valves, Pumps, and for Components and

Appurtenances Containing Brazed Joints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69NH-6324 Pneumatic Test Pressure Holding Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

NH-6400 Pressure Test Gages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

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ARTICLE NH-6000TESTING

NH-6100 GENERAL REQUIREMENTS

Testing of Section III, Division I, Class 1 componentswhen metal temperatures exceed those for which allow-able stress values are given in Section II, Part D, shallbe in accordance with the rules of this Subsection.

NH-6110 SCOPE OF TESTING

NH-6111 General Hydrostatic and PneumaticTest Media

(a) The selection of a particular test medium maydepend upon considerations in (b), (c), and (d) below.For some items, a combination of gaseous and liquidtest media may be desirable.

(b) Compared to pressurized liquids, gas under asimilar pressure has a greater potential energy release.It is therefore recommended that special precautionsfor protection of personnel be taken when a gas underpressure is used as a test medium.

(c) Some components, appurtenances, or systems arenot designed to support the liquid weight required ina hydrotest. Pneumatic tests should be considered forsuch components.

(d) The use of liquids for testing often results intraces of the liquid left in hard-to-clean places in thesystem, and these residues may be harmful to thestructural material because of reactions involving theresidues and the system coolant. Pneumatic tests shouldbe considered under these circumstances.

NH-6112 Pressure Testing of Components andAppurtenances

(a) Except as noted in (b) and (c) below, all compo-nents and appurtenances for elevated temperature serviceshall be static pressure tested in the presence of theInspector.

(b) Nuts, bolts, studs, and gaskets are exempt fromthe rules of this Subsection.

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(c) A static pressure test of each line valve andpump with inlet piping connections of 4 in. nominalpipe size and smaller shall be performed by the Manu-facturer and so noted on the Data Report Form; however,this static pressure test need not be witnessed by theInspector. The Inspector’s review of the Manufacturer’stest records will be his authority to sign the report.This takes precedence over NCA-5280.

(d) Under the special conditions of NH-6117 andNH-6118, a helium mass spectrometer leak test (plusother tests) may replace the static pressure test requiredin (a) above.

(e) The requirements of (a) above are met by meetingthe requirement of NH-6113(a).

(f) The component or appurtenance pressure test,when conducted in accordance with the rules of NH-6221 or NH-6321, shall be acceptable as a pressuretest for parts and piping subassemblies.

(g) For components and appurtenances which willbe subjected to external pressure loads in service, thepressure test requirement in (a) above may be performedon the basis of an internal pressure test using the rulesof NH-6221 or NH-6321. The Design Specificationsmay require further tests to demonstrate structural integ-rity under external pressure loading.

NH-6113 Pressure Testing of Systems

(a) Prior to initial operation, the installed Class 1system shall be static pressure tested in the presenceof the Inspector.

(b) Under the special restrictions of NH-6117 andNH-6118, a helium mass spectrometer leak test mayreplace the static pressure test in (a) above.

NH-6115 Time of Pressure Test and Stampingof Components and Appurtenances

(a) The pressure tests of components and appurte-nances required by NH-6112(a) shall be performed

NH-6115 1998 SECTION III, DIVISION 1 — NH NH-6122

prior to installation in the system as specified in NH-6221(a) or NH-6321(a).

(b) The pressure tests of components and appurte-nances required by NH-6112(a) may be performed afterinstallation if the system pressure test is used underthe provisions of NH-6221(c) or NH-6321(c).

(c) The Data Report Form shall not be completednor signed by the Inspector and the components shallnot be stamped until the component Manufacturer hasconducted the static pressure test.

(d) Specially designed welded seals,1 which are iden-tified on the Data Report Form as being welded bythe Installer under the rules of NH-6118, need not betested prior to the stamping of the component.

(e) Appurtenances containing brazed joints, pumpsnot designed by detailed analysis,1 and valves shall bestatic pressure tested prior to installation in a system.

NH-6116 Machining of Local Areas After StaticPressure Testing

(a) In local regions of the pressure boundary wheretight tolerances are required for proper componentfunctioning, extra wall thickness is permitted duringpressure testing. If extra wall thickness is providedduring fabrication, the excess material may be machinedto critical dimensions and tolerances after completionof the static pressure test.

(b) The extra wall thickness permitted during pressuretesting in (a) above shall not exceed 10% of the finalwall thickness or3⁄8 in. (10 mm), whichever is less.

(c) The final wall thickness, after machining to criti-cal dimensions and tolerances, shall comply with theminimum wall thickness requirements defined in therules for design of Class 1 components for elevatedtemperature service.

NH-6117 Alternative Tests of Closure Weldsand Access Hatches

(a) Closure welds for access hatches in vessels andclosure welds for connecting piping subassemblies maybe tested by an alternative procedure for the pressuretest requirements of NH-6112 and NH-6113 providedthe conditions of (1) through (4) below are met:

(1) If hydrotesting were to be used, residues fromthe hydrotest liquid could be deleterious to the service;

(2) Closure welds are located at least 3√RT frommajor structural discontinuities such as flanges, largenozzles, pumps, or valves.R is the mean radius and

1 Definitions are contained in the rules governing the design of Class1 components in elevated temperature service.

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T is the nominal thickness of the thicker materialadjacent to the weld;

(3) The alternative test procedure in (b) below isspecified for the closure welds; and

(4) The closure welds to which the alternativetests shall be applied, and the alternative test procedureshall be included in the Design Specification. Theclosure welds to which the alternative test procedurehas been applied shall be identified on the Data Report.

(b) As an alternative to the pressure test procedure,closure welds may be tested by a mass spectrometerhelium leak test.

NH-6118 Alternative Tests at SpeciallyDesigned Welded Seals

(a) Specially designed welded seals, such as omegaand canopy seals, need not meet the pressure testrequirements of NH-6112 and NH-6113 when:

(1) The final weld cannot be completed until afterthe hydrostatic or pneumatic test because the systemtest pressure would exceed the limit specified for anysystem component; and

(2) The seal is subjected to a leak test at themaximum normal operating pressure.

(b) Welds of specially designed welded seals maybe tested by a helium leak test in lieu of the pressuretest requirements of NH-6112 and NH-6113 provided:

(1) The welds of the seal, and the welds joiningthe seal to the component or supporting structure, cannotbe visually examined during testing due to accessrestrictions; and

(2) The welds and the alternative test procedureshave been mutually agreed to by the Owner and Manu-facturer, and the requirements appear in the DesignSpecifications and in the Installer’s Data Report Forms.

NH-6120 PREPARATION FOR TESTING

NH-6121 Exposure of Joints

All mechanical and welded joints, including welds,shall be left uninsulated and exposed for examinationduring the test.

NH-6122 Addition of Temporary Supports

Components designed for vapor or gas may be pro-vided with additional temporary supports, if necessary,to support the weight of the test liquid.

NH-6123 ARTICLE NH-6000 — TESTING NH-6215

NH-6123 Restraint or Isolation of ExpansionJoints

Expansion joints shall be provided with temporaryrestraint, if required for the additional pressure loadunder test, or they shall be isolated from the test.

NH-6124 Isolation of Equipment Not Subjectedto Pressure Test

Equipment that is not to be subject to the pressuretest shall be either disconnected from the componentor system, or isolated by a blank flange or similarmeans. Valves may be used if the valve with its closureis suitable for the proposed test pressure.

NH-6125 Treatment of Flanged JointsContaining Blinds

Flanged joints at which blinds are inserted to blankoff other equipment during the test need not be testeduntil the blinds are removed.

NH-6126 Precautions Against Test MediumExpansion

If a pressure test is to be maintained for a periodof time and the test medium in the system is subjectto thermal expansion, precautions shall be taken toavoid excessive pressure. A small relief valve set to1.33 times the test pressure is recommended duringthe pressure test.

NH-6200 HYDROSTATIC TESTS

NH-6210 HYDROSTATIC TESTINGPROCEDURE

NH-6211 Provision of Air Vents at High Points

Vents shall be provided at all high points of thecomponent or system in the position in which the testis to be conducted to purge air pockets while thecomponent or system is filling.

NH-6212 Test Medium and Test Temperature

(a) Any nonhazardous liquid at any temperature be-low its boiling point may be used for the hydrostatictest. Combustible liquids having a flash point less than100°F, such as petroleum distillates, may be used onlyfor tests at near atmospheric temperature.

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(b) No hydrostatic test shall be performed at a temper-ature which exceeds those for whichSm values arelisted in Tables 2A and 2B of Section II, Part D,Subpart 1 for any of the materials used in the pressureboundaries of components being tested.

(c) It is recommended that the test be made at atemperature that will minimize the possibility of brittlefracture (NB-2330). The test pressure shall not beapplied until the component, appurtenance or system,and the pressurizing medium are approximately at thesame temperature.

(d) For the vessel hydrostatic test before installation,it is recommended that the test be made at a temperaturenot lower than [RTNDT + 60°F], (NB-2331).

NH-6213 Check of Test Equipment BeforeApplying Pressure

The test equipment shall be examined before pressureis applied to ensure that it is tight and that all lowpressure filling lines and other appurtenances that shouldnot be subjected to the test pressures have been discon-nected or isolated by valves or other suitable means.

NH-6215 Examination for Leakage AfterApplication of Pressure

Following the application of the hydrostatic testpressure for a minimum of 10 minutes, as required byNH-6224, examination for leakage shall be made ofall joints, connections, and of all regions of high stresssuch as regions around openings and thickness transitionsections. Except in the case of pumps and valves,which shall be examined while at test pressure, thisexamination shall be made at a pressure equal to thegreater of the design pressure or three-fourths of thetest pressure and it shall be witnessed by the Inspector.Leakage of temporary gaskets and seals, installed forthe purpose of conducting the hydrostatic test and whichwill be replaced later, may be permitted unless theleakage exceeds the capacity to maintain system testpressure for the required amount of time. Other leaks,such as from permanent seals, seats, and gasketed jointsin components, may be permitted when specificallyallowed by the Design Specifications. Leakage fromtemporary seals or leakage permitted by the DesignSpecifications shall be directed away from the surfaceof the component to avoid masking leaks from otherjoints.

NH-6220 1998 SECTION III, DIVISION 1 — NH NH-6313

NH-6220 HYDROSTATIC TEST PRESSUREREQUIREMENTS

NH-6221 Minimum Required SystemHydrostatic Test Pressure

(a) Except as may be otherwise required by materialspecifications and by the requirements of NH-6223, allcomponents and appurtenances shall be subjected to ahydrostatic test at a pressure not less than 1.25 timesthe system design pressure prior to installation in thenuclear power system.

(b) All pressure retaining components of the com-pleted Class 1 system shall be subjected to a systemhydrostatic test at a pressure not less than 1.25 timesthe system design pressure unless specifically exceptedunder the provisions of NH-6117 and NH-6118.

(c) The system hydrostatic test of NH-6221(b) maybe substituted for a component hydrostatic test of NH-6221(a) provided:

(1) The component can be repaired by welding,if required, as a result of the system hydrostatic test,in accordance with the rules of NB-2500;

(2) The component repair can be postweld heattreated, if required, and nondestructively examined inaccordance with rules of NB-2500, NB-5100, and NB-5400, as applicable, subsequent to the system hydrostatictest; and

(3) The component is subjected to the requiredsystem hydrostatic test following the completion ofrepair and examination.

NH-6222 Maximum Permissible HydrostaticTest Pressure

(a) The stress limits, contained in the rules of NH-3000, shall be used in determining the permissiblehydrostatic test pressure. In multichamber components,pressure may be simultaneously applied to the appro-priate adjacent chamber to meet these stress limits. Thenumber of test sequences for which the above provisionsmay be considered applicable shall not exceed ten.

(b) When hydrostatically testing a system, the testpressure shall not exceed the lowest of the maximumtest pressures allowed for any of the components inthe system.

NH-6223 Hydrostatic Test Pressure for Valves,Pumps, and for Components andAppurtenances Containing BrazedJoints

(a) Prior to installation, valves, pumps not designedby detailed stress analysis, and other components and

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appurtenances containing brazed joints shall be hydro-statically tested at a pressure 1.5 times the systemdesign pressure.

(b) The inlet (primary pressure containing) portionof safety and safety relief valves shall be hydrostaticallytested at a pressure at least 1.5 times the set pressuremarked on the valve. For closed system applications,the outlet portion of safety and safety relief valvesshall be hydrostatically tested to 1.5 times the designsecondary pressure of the outlet system.

NH-6224 Hydrostatic Test Pressure HoldingTime

The hydrostatic test pressure shall be maintained fora minimum total time of 10 minutes and for suchadditional time as may be necessary to conduct theexamination for leakage required by NH-6215. Whentesting pumps, valves, and other components coveredby NH-6223, the pressure shall be maintained a mini-mum of 15 minutes for each inch of design minimumwall thickness, but for not less than 10 minutes.

NH-6300 PNEUMATIC TESTS

NH-6310 PNEUMATIC TESTINGPROCEDURES

NH-6311 General Requirements

When a pneumatic test is performed, it shall beconducted in accordance with the requirements of NH-6300 and NH-6112.

NH-6312 Test Medium and Test Temperature

(a) The gas used as the test medium shall be non-flammable;

(b) It is recommended that the test be made at atemperature that will minimize the possibility of brittlefracture (NB-2330). The test pressure shall not beapplied until the component, appurtenance or system,and the pressurizing medium are approximately thesame temperature.

NH-6313 Check of Test Equipment BeforeApplying Pressure

The test equipment shall be examined before pressureis applied to ensure that it is tight and that all appurte-nances that should not be subjected to the test pressurehave been disconnected or isolated by valves or othersuitable means.

NH-6314 ARTICLE NH-6000 — TESTING NH-6400

NH-6314 Procedure for Applying Pressure

The pressure in the system shall gradually be in-creased to not more than one-half of the test pressure,after which the pressure shall be increased in steps ofapproximately one-tenth of the test pressure until therequired test pressure has been reached. The pressureshall then be reduced to a value equal to the greaterof the design pressure or three-fourths of the testpressure and held for a sufficient time to permit examina-tion of the system in accordance with NH-6315.

NH-6315 Examination for Leakage AfterApplication of Pressure

Following the application of pressure for the timespecified in NH-6324, examination of leakage in accord-ance with NH-6215 shall be made.

NH-6320 PNEUMATIC TEST PRESSUREREQUIREMENTS

NH-6321 Minimum Required System PneumaticTest Pressure

(a) Except as may be otherwise required by materialspecifications and by the requirements of NH-6323, allcomponents and appurtenances shall be subjected to apneumatic test at a pressure not less than 1.20 timesthe system design pressure prior to installation in thenuclear power system.

(b) All pressure retaining components of the com-pleted Class 1 system shall be subjected to a systempneumatic test at a pressure not less than 1.20 timesthe system design pressure unless specifically exceptedunder the provisions of NH-6117 and NH-6118.

(c) The system pneumatic test of NH-6321(b) maybe substituted for a component pneumatic test of NH-6321(a) provided:

(1) The component can be repaired by welding,if required as a result of the system pneumatic test,in accordance with the rules of NB-4400;

(2) The component repair can be postweld heattreated, if required, and nondestructively examined inaccordance with the rules of NB-4400, NB-5100, andNB-5400, as applicable, subsequent to the system pneu-matic test; and

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(3) The component is subjected to the requiredsystem pressure test following the completion of repairand examination.

NH-6322 Maximum Permissible Pneumatic TestPressure

(a) The stress limits contained in the rules of NH-3000 shall be used in determining the permissiblepneumatic test pressure. In multichamber components,pressure may be simultaneously applied to the appro-priate adjacent chamber to meet these stress limits. Thenumber of test sequences for which the above provisionsmay be considered applicable shall not exceed ten.

(b) When pneumatically testing a system, the testpressure shall not exceed the lowest of the maximumtest pressures allowed for any of the components inthe system.

NH-6323 Pneumatic Test Pressure for Valves,Pumps, and for Components andAppurtenances Containing BrazedJoints

(a) Prior to installation, valves, pumps not designedby detailed stress analysis, and other components andappurtenances containing brazed joints shall be pneu-matically tested at a pressure 1.5 times the systemdesign pressure.

(b) The inlet (primary pressure containing) portionof safety and safety relief valves shall be pneumaticallytested at a pressure at least 1.5 times the set pressuremarked on the valve. For closed system applications,the outlet portion of safety and safety relief valvesshall be pneumatically tested to 1.5 times the designsecondary pressure of the outlet system.

NH-6324 Pneumatic Test Pressure HoldingTime

The pneumatic test shall be maintained for a minimumtotal time of 10 minutes and for such additional timeas may be necessary to conduct the examination forleakage required by NH-6215.

NH-6400 PRESSURE TEST GAGES

The rules of NB-6400 shall apply.