Hydrotest Pressure
/glossary/hydrotest-pressureLiquid-pressure test of a pipe or assembled line under the governing product standard or approved procedure.
Kanpur PWD, JJM, and fire-system buyers meet two different tests: the mill leak-proof test on IS 1239 at 5 MPa on each tube, and a later site test under the project code. Those two numbers are not interchangeable. Offers from RP Sales are ex-warehouse Kanpur, GST 18% extra as the budgeting basis; the tax invoice applies the rate in force.
In detail
Hydrotest pressure is the liquid pressure applied to a pipe length, tube, or assembled system under a written procedure. A mill test follows the purchased product standard. The BIS product-manual certificate for IS 1239 (Part 1):2004 states each steel tube is eddy-current or hydrostatically tested to 5 MPa. ASTM A530/A530M-18 Section 22 sets mill hydrostatic pressure for specialised carbon and alloy pipe as P = 2St/D, with S at 60 percent of specified minimum yield for carbon and ferritic grades, then applies the stated caps and a minimum 5 s hold. A site leak test follows the design code, not that mill clause. Record the actual pressure, medium, duration, and result on the inspection document.
What hydrotest pressure is, and what it is not
A hydrostatic test fills the object with liquid, raises it to a named pressure, holds that pressure, and looks for leakage or permanent deformation. The object may be one mill length or a completed piping system. The procedure owns the medium, boundary, gauges, duration, and acceptance.
A mill product test and a site system test use different clauses. The BIS product manual for IS 1239 (Part 1):2004 prints 5 MPa on the specimen certificate and requires a leak-proof test on each tube (Clause 13). ASTM A106/A106M-26 lists hydrostatic testing among the mechanical tests; the mill pressure itself sits in the general-requirements formula when that specification invokes it.
Hydrotest pressure is not a working-pressure stamp. It is not a schedule number. It is not a substitute for chemistry or tensile results on the MTC. A length that held 5 MPa at the mill can still fail a later site test after welding, threading, or flange makeup.
Pneumatic testing is a different method. Use it only when the governing code and the approved risk assessment allow gas instead of liquid.
Who needs a mill hydro, and who needs a site hydro
Every IS 1239 tube in a Kanpur JJM or PWD water lot needs the mill leak-proof test on the certificate. Fire-system installers in Fazalganj and Chakeri still need that mill record, plus the site test the fire drawing names after the riser is built.
Panki process shops that weld A106 Sch 40 spools need the mill hydrostatic or the permitted nondestructive-electric alternative on each length, then a B31.3 leak test on the assembled line. Sugar-mill IBR tubes take the mill test on Form III-B. Steam pipe takes Form III-A. Mountings and fittings take Form III-C.
Do not treat a mill 5 MPa IS 1239 result as the site test for a welded hydrant header. Do not treat a B31.3 system test as proof that an untested replacement length left the mill.
Dada Nagar hydraulic barrels are not hydrotested as line pipe. Those shops design on remaining wall after honing or skiving and follow the cylinder standard, not IS 1239 Clause 13.
Mill test pressures used on Kanpur pipe lots
The table separates mill product tests the buyer will actually see on an MTC. Each row is one standard. Copy that row onto the RFQ; do not blend them.
| Product | Mill hydro basis | Hold or note | Typical Kanpur use |
|---|---|---|---|
| IS 1239 Part 1 | 5 MPa leak-proof; 50 kg/cm² on the site class table | Each tube; at least 3 s on the standards hub | JJM, PWD, plumbing, GI |
| ASTM A106 / A530 | P = 2St/D, S = 60% of SMYS, then the A530 caps | Minimum 5 s, no leakage through the wall | Panki process spools |
| ASTM A53 | Hydrostatic without leakage through weld or body | Or the permitted NDE alternative | Utility and export A53 |
| IS 4270 casing | Calculated, capped at 7 MPa | At least 3 s, no leakage | Borewell contractors |
| IS 3589 | Hydraulic pressure test, Clause 10, each pipe | NDT may replace hydro if buyer and mill agree | Trunk water and sewage |
The 50 kg/cm² figure on the IS 1239 class table applies to Light, Medium, and Heavy. It is not a 50 bar Light / 75 bar Medium split. 5 MPa is the certificate wording on the IS 1239 (Part 1) product manual.
How to specify the test on an RFQ
Write the mill test and the site test as two lines when both apply. A single word hydro on a mixed A106 and IS 1239 BOQ is how the wrong pressure lands on the MTC.
- Product: standard, grade, NB or NPS, wall or class, length, quantity, ends, coating.
- Mill test: name the clause. IS 1239 leak-proof 5 MPa. A106 hydrostatic or NDE. IS 3589 Clause 10.
- Site test: name the design code and the approved procedure, not the mill number.
- Medium: water unless the procedure names another liquid. Drain and dry when the lining or the process forbids leftover water.
- Documents: EN 10204 3.1 with the hydro or NDE result. Form III-A, III-B, or III-C by component, not by habit.
- Witness: third-party inspection by SGS, Bureau Veritas, Lloyds, or TUV whenever the ITP names the agency.
- Handover of the tested lengths at the Kanpur yard, or FOR the named city. Add GST 18% extra on the tested steel.
Worked mill-pressure example on 2 inch Sch 40 Grade B
ASTM A530/A530M-18 Section 22 uses P = 2St/D. For carbon and ferritic pipe, S is 60 percent of specified minimum yield. A106 Grade B yield on this site is 240 MPa, so S = 0.60 × 240 = 144 MPa.
The site schedule chart gives 2 inch NPS as OD 60.3 mm and Sch 40 wall 3.91 mm. P = 2 × 144 × 3.91 / 60.3 = 18.68 MPa (rounded). Section 22 rounds values at or above 7 MPa to the nearest 1 MPa, and separately caps the minimum required pressure at 17.0 MPa for outside diameters of 88.9 mm or less. The mill minimum for this length is therefore 17.0 MPa, held at least 5 s, with no leakage through the wall.
Theoretical mass on the same wall is W = (60.3 − 3.91) × 3.91 × 0.02466 = 5.44 kg/m. Sixteen 6 m lengths are 16 × 6 × 5.44 = 522.24 kg. The seamless price list band for 2 inch Sch 40 is ₹80-98 per kg ex-warehouse Kanpur as of 24 May 2026. That steel line is 522.24 × 80 = ₹41,779 to 522.24 × 98 = ₹51,180 before GST and freight.
This 17.0 MPa mill figure is not the site leak-test pressure for a Panki spool. The assembled line uses the design-code calculation.
Common hydrotest mistakes in procurement
In practice, the first failure is copying 5 MPa from an IS 1239 MTC onto an A106 isometric. The A530 example above is a different product and a different number.
The second failure is treating a mill hydro as a site hydro. Welds, threads, and gaskets added after the mill test still need the project procedure.
The third failure is accepting an MTC that omits the hydro or NDE line. The IS 1239 receiving note on this site already treats a missing hydrotest record as a hold. Match stencil, bundle tag, and certificate before the truck leaves.
The fourth failure is using the IS 4270 7 MPa cap on a water-main IS 3589 length. Casing and trunk main are different standards. See drill and borewell pipes in Kanpur for the casing clause.
Standards and clauses for the test
IS 1239 (Part 1):2004 Clause 13 is the leak-proof test. The product manual specimen certificate states each steel tube is eddy-current or hydrostatically tested to 5 MPa. The site standards hub also records a hold of at least 3 seconds for that leak-proof summary.
ASTM A530/A530M-18 Section 22 is mandatory when a product specification requires hydrostatic testing without defining the parameters. It gives P = 2St/D, the 60 percent and 50 percent stress bases, the 17.0 MPa and 19.0 MPa caps, and the 5 s hold.
ASTM A106/A106M-26 and ASTM A53/A53M-24 both name hydrostatic testing on their public abstracts. A53 requires no leakage through the weld seam or the pipe body. ASME B31.3 covers examination, inspection, and testing of process piping, including the hydrostatic leak test for metallic piping, and is a system test, not a mill certificate line.
The DPIIT forms index used on this site maps steam pipe to Form III-A, tubes to Form III-B, and mountings or fittings to Form III-C. The chosen form records the tests the authority requires. It is not a generic hydro sticker.
Buying hydrotested pipe in Kanpur
JJM and PWD contractors collecting IS 1239 from Bartan Bazar should see 5 MPa, or the eddy-current alternative, on the certificate that travels with the bundle. Fire installers in Fazalganj still add the site test after erection. Intra-city runs to Panki (about 12 km) and Jajmau (about 10 km) leave from the same yard.
See steel pipes in Kanpur, MS ERW pipe supplier Kanpur, GI pipes in Kanpur, and the hydrostatic testing procedure. Bartan Bazar market notes sit on the Kanpur steel market page.
A witnessed mill hydro on an indent heat follows the mill-direct window on the glossary lead-time entry, 14-21 days for standard grades. Stocked IS 1239 that already carries the mill test leaves in 3-7 days.
Mill test versus site system test
The mill tests the length between the mill end-seals. The site tests the boundary the procedure draws: welds, valves, flanges, and any temporary blinds. A clean mill chart does not close a leaking field flange.
ASME B31.3 is the process-piping code and governs the hydrostatic leak test for an assembled metallic line. It uses design pressure and allowable-stress ratios from the adopted edition. That calculation is not P = 2St/D from A530, and it is not the IS 1239 5 MPa mill figure.
For an IBR steam line leaving Kanpur, the authority route and Form III-A sit beside the mill hydro. For a tube bank, Form III-B sits beside it. Do not file Form III-C against the tube heat.
Gauges, hold, and incoming checks
Read the pressure, the hold, and the result on the certificate. For IS 1239, the expected mill wording is 5 MPa or eddy current. For A106, expect the calculated or capped mill pressure recorded on the MTC.
At the Kanpur yard, TPI matches stencil, heat, OD, wall, and the hydro line to the PO. That walk-around cannot recreate a mill test that never happened. Failed lengths stay segregated. Raise a rejection note with the failed check and the governing clause.
Site gauges need current calibration status under the project procedure. Copy the ITP.
Documents that travel with a tested bundle
EN 10204 3.1 is the usual mill sheet. It should name the hydro or NDE result for that heat or control unit. Type 3.2 adds an independent countersignature when the ITP asks for it.
The dispatch challan lists sizes and heats so the Lucknow or Prayagraj store can match steel to paper. The mill sheet with the hydro or NDE line travels in that same pack.
Coated IS 3589 or GI lots need the coating report as a second sheet. Zinc mass and holiday tests are not the hydro line. Keep them separate on the RFQ.
Where you'll meet this in procurement
You will meet Hydrotest Pressure on size charts, mill quotes, and fitment checks. Cross-check Hydrotest Pressure against OD, wall thickness or schedule, length, and end finish so the delivered pipe matches flanges, fittings, and pressure duty—not just a familiar nominal label.
Related terms
Related resources
- Pipe schedule chart
- Steel pipe weight calculator
- Hydrostatic testing procedure
- IS 1239 Part 1
- ASTM A106
- Steel pipes in Kanpur
- MS ERW pipe supplier Kanpur
- GI pipes in Kanpur
- Seamless pipe price list
- Kanpur steel market
- Borewell pipes in Kanpur
- Quality and documentation
- Request a quotation (RFQ)
- Back to full glossary
Key points
- A mill hydro and a site leak test use different clauses and can use different pressures.
- IS 1239 Part 1 mill leak-proof testing on the BIS product-manual certificate is 5 MPa on each tube.
- A530 Section 22 uses P = 2St/D with S at 60 percent of SMYS for carbon and ferritic pipe, then applies caps.
- 2 inch Sch 40 Grade B on that formula caps at 17.0 MPa for OD 60.3 mm. That is not the site test.
- Tested lots from the Kanpur yard budget GST 18% extra. Record the actual test on the MTC.
Frequently asked questions
Sources
- PM/1239 (Part 1)/4 Feb 2022. Product Manual for Steel Tubes according to IS 1239 (Part 1):2004: specimen certificate: each steel tube eddy-current or hydrostatically tested to 5 MPa; Clause 13 leak-proof test on each tube (Bureau of Indian Standards)
- ASTM A530/A530M-18. General Requirements for Specialized Carbon and Alloy Steel Pipe, Section 22 hydrostatic test: P = 2St/D, 60% SMYS carbon/ferritic, caps 17.0 MPa / 19.0 MPa, 5 s hold (ASTM International)
- ASTM A106/A106M-26. Seamless Carbon Steel Pipe for High-Temperature Service: public abstract names hydrostatic and nondestructive electric tests (ASTM International)
- ASTM A53/A53M-24. Public abstract: hydrostatic testing without leakage through the weld seam or the pipe body (ASTM International)
- ASME B31.3-2024. Process Piping: code covering examination, inspection, and testing, including the hydrostatic leak test for metallic piping (American Society of Mechanical Engineers)
- IS 4270:2001. Steel tubes used for water wells: Clause 8 calculated hydrotest, maximum 7 MPa, hold at least 3 seconds, as used on this site (Bureau of Indian Standards)
- PM/IS 3589:2001. Hydraulic pressure test Clause 10 on each pipe; NDT may substitute when agreed (Bureau of Indian Standards)
- Indian Boiler Regulations, 1950. Forms index: III-A steam pipes, III-B tubes, III-C boiler mountings and fittings (Central Boilers Board, Government of India)