\n5<\/td>\n 20 \u00b0C \/ 14 + 60 \u00b0C \/ 25 + 80 \u00b0C \/ 10<\/td>\n 90 \u00b0C \/ 1<\/td>\n 100 \u00b0C \/ 100<\/td>\n High temperature radiators<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nClass 3 exists \u2014 low-temperature underfloor heating \u2014 but the standard restricts it, and the restriction is instructive. Its footnote reads “Only allowed when the malfunction temperature cannot rise above 65 \u00b0C.” In most buildings nobody can guarantee that, which is why class 3 is rare on real tenders and class 4 does the underfloor work instead.<\/p>\n
Three consequences buyers miss<\/h3>\n First, the classes are guidance. ISO 10508 clause 4 says plainly that the applications “are given as guidance and are not requirements. In countries with extreme weather conditions other classes may be preferred.” A Gulf project specifying a higher class than the table suggests is not over-engineering; it is doing what the standard invites.<\/p>\n
Second, every class carries cold water for free. The same clause requires that any system meeting one of the five classes “shall also be suitable for the transportation of cold water for a period of 50 years at a temperature of 20 \u00b0C and a design pressure of 10 bar.” So a class 5 pipe is automatically qualified for the cold line. You never need to buy a separate cold-water specification.<\/p>\n
Third, a shorter design life scales the profile \u2014 with one exception. If the specified service life is under 50 years, “all the times given in Table 1 shall be reduced by a proportionate amount, except for the time for malfunction, which shall remain at 100 h.” The malfunction allowance is absolute. A 25-year system still has to survive the same 100 hours at 100 \u00b0C, because a failed thermostat does not care how long the building was designed to last.<\/p>\n
How a wall thickness is actually chosen under ISO 15874-2<\/h2>\n This is the mechanism the SERP does not explain, and it is one sentence. ISO 15874-2:2013 clause 6.2.2: “For any particular class of service conditions, design pressure and nominal size, the minimum wall thickness, emin<\/sub>, shall be chosen in such a way that the corresponding S series or Scalc<\/sub>-value is equal to or less than the values of Scalc,max<\/sub> given in Table 1, 2, 3 or 4.”<\/p>\nTable 3 is the PP-R one. It is small, it is the entire selection logic for the material you are buying, and virtually no supplier datasheet reproduces it.<\/p>\n
\n\n\nDesign pressure pD<\/sub><\/th>\nClass 1<\/th>\n Class 2<\/th>\n Class 4<\/th>\n Class 5<\/th>\n<\/tr>\n<\/thead>\n \n\n4 bar<\/td>\n 6,9<\/td>\n 5,3<\/td>\n 6,9<\/td>\n 4,7<\/td>\n<\/tr>\n \n6 bar<\/td>\n 5,0<\/td>\n 3,5<\/td>\n 5,5<\/td>\n 3,2<\/td>\n<\/tr>\n \n8 bar<\/td>\n 3,8<\/td>\n 2,6<\/td>\n 4,1<\/td>\n 2,4<\/td>\n<\/tr>\n \n10 bar<\/td>\n 3,0<\/td>\n 2,1<\/td>\n 3,3<\/td>\n 1,9<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nTwo features of this table repay a slow read. Class 4 is less<\/em> demanding than class 2 at every pressure \u2014 3,3 against 2,1 at 10 bar \u2014 because class 4 spends most of its 50 years at 20 \u00b0C and 40 \u00b0C, while class 2 sits at 70 \u00b0C for 49 of them. Underfloor heating is thermally gentler than a hot-water riser, and the standard prices it accordingly. <\/p>\nAnd class 5 at 10 bar demands Scalc,max<\/sub> 1,9, against 3,0 for class 1. Wall thickness relates to the series as e = dn<\/sub>\/(2S+1), so a lower ceiling forces a thicker wall \u2014 but you do not buy the formula’s answer, you buy the next catalog series that satisfies it. On DN63 that means class 5 lands on S2 at 12,7 mm while class 1 clears at S3,2 and 8,6 mm: 48 % more wall<\/strong> at the same diameter and the same 10 bar. High-temperature radiators are an expensive thing to discover late in a tender.<\/p>\nA worked example you can reuse<\/h3>\n Take a real question: DN32 PP-R on a 10-bar hot-water riser, class 2. Table 3 gives Scalc,max<\/sub> = 2,1. So the S-series must be 2,1 or lower \u2014 S2,5 is too high<\/em> and fails, and you drop to S2. In ISO 15874-2 Table 5, dimension class A, DN32 at S2 is emin<\/sub> 6,5 mm.<\/p>\nNow run the same DN32 at 10 bar as class 1 hot water supply. Scalc,max<\/sub> = 3,0, so S2,5 (5,4 mm) is admissible. That is the whole difference between a 5,4 mm wall and a 6,5 mm wall \u2014 one line in the service-class column. In resin terms the wall cross-section goes from 451 mm\u00b2 to 521 mm\u00b2, so class 2 costs about 15 % more material per metre<\/strong> at the same diameter and the same 10 bar.<\/p>\nThat is the arithmetic deciding whether a rival quote is cheap or non-conforming, and it is why “PN20” on its own answers nothing: PN20 corresponds to S2,5, which is correct at class 1 and wrong at class 2.<\/p>\n
Two more clauses complete the geometry. Clause 6.2.2 also sets an absolute floor that overrides the arithmetic: “pipes intended to be joined together by fusion shall have a minimum wall thickness of 2,0 mm.” Since virtually all PPR is socket-fused, that rule quietly deletes the thinnest options at small diameters regardless of what the pressure calculation allows. And clause 6.1 requires that dimensions “shall be measured in accordance with ISO 3126” \u2014 so an incoming-inspection dispute over how the caliper was used has a named referee.<\/p>\n
\n
The dimension class nobody asks about.<\/strong> ISO 15874-2 carries four dimension classes, and they are not interchangeable. Table 5 is class A, “sizes in accordance with ISO 4065:1996”, which is the DN20\/25\/32 range the global PPR trade runs on. Tables 6 and 7 are classes B1 and B2, “sizes based on copper pipe sizes” \u2014 10, 12, 15, 18, 22, 28, 35 mm \u2014 used where PPR replaces copper. Table 8 is class C, “non-preferred pipe sizes used for example for heating systems”.<\/p>\nIf a European enquiry asks for 22 mm PPR and your catalogue only runs class A, you are not looking at the same product family, and the marking table requires the class to be printed on the pipe precisely so this cannot be fudged.<\/p>\n<\/div>\n
The tests a mill has to pass \u2014 and what OIT is not<\/h2>\n Specification arguments usually end at dimensions, because dimensions are what a buyer can measure on a pallet. The requirements that actually determine whether the pipe lasts 50 years are in clauses 7 and 8, and they are type tests \u2014 done once on a material and production route, not on your container.<\/p>\nPPR ISO plug fitted for hydrostatic pressure testing, the method ISO 15874-2 Table 10 specifies for resistance to internal pressure<\/figcaption><\/figure>\nClause 7 covers resistance to internal pressure. For PP-R, ISO 15874-2 Table 10 sets four separate hydrostatic tests, all requiring no failure during the test period, on three test pieces each, water-in-water with a Type A end cap:<\/p>\n
\n\n\nHoop stress<\/th>\n Temperature<\/th>\n Period<\/th>\n What it proves<\/th>\n<\/tr>\n<\/thead>\n \n\n16,0 MPa<\/td>\n 20 \u00b0C<\/td>\n 1 h<\/td>\n Short-term burst strength<\/td>\n<\/tr>\n \n4,3 MPa<\/td>\n 95 \u00b0C<\/td>\n 22 h<\/td>\n Hot short-term behaviour<\/td>\n<\/tr>\n \n3,8 MPa<\/td>\n 95 \u00b0C<\/td>\n 165 h<\/td>\n Onset of the ductile-brittle transition<\/td>\n<\/tr>\n \n3,5 MPa<\/td>\n 95 \u00b0C<\/td>\n 1 000 h<\/td>\n The long-term anchor point<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nThe 1 000-hour test at 95 \u00b0C is the one to ask for by name. It takes six weeks of continuous testing and it is the point on the curve where a badly stabilised compound gives itself away. A mill that can hand you a current type-test report against that line has spent real money; a mill that offers only a 20 \u00b0C burst figure has tested the easy one.<\/p>\n
Why there is no OIT number on this page<\/h3>\n Oxidation induction time gets quoted constantly in PPR sales conversations, usually as “our OIT is over 20 minutes”. It is a legitimate laboratory measurement of how long a sample resists oxidation at a fixed temperature under oxygen, and it is a genuine proxy for antioxidant package quality. But ISO 15874-2:2013 does not require it.<\/strong> Clause 8 and its Table 11 specify exactly four physical and chemical characteristics \u2014 longitudinal reversion, thermal stability by hydrostatic pressure testing, impact resistance and melt flow rate. Oxidation induction time is not among them.<\/p>\nWhat the standard uses instead is heavier. Thermal stability for PP-R is proved by hydrostatic pressure testing at 1,9 MPa hoop stress, 110 \u00b0C, water-in-air, for a test period of 8 760 hours<\/strong> \u2014 one full year of continuous testing on a single test piece, with the requirement being no bursting during the period. <\/p>\nThat is the standard’s answer to “will the stabiliser package survive”. An OIT figure quoted at you is not a conformity claim under ISO 15874-2; it is supplementary evidence. Treat a supplier who leads with OIT and cannot produce the 8 760-hour result accordingly.<\/p>\n
The rest of Table 11 is straightforwardly checkable and worth putting on an inspection scope:<\/p>\n
\nLongitudinal reversion \u2264 2 %<\/strong>, by Method B of ISO 2505 (oven test). The PP-R test temperature is 135 \u00b0C \u2014 note that PP-H and PP-B are tested at 150 \u00b0C, so a report at 150 \u00b0C is not a PP-R report. Exposure runs 1 h for en<\/sub> \u2264 8 mm, 2 h for 8 mm < en<\/sub> \u2264 16 mm, and 4 h above that, on 3 test pieces.<\/li>\nMelt flow rate of the compound \u2264 0,5 g\/10 min<\/strong> at 230 \u00b0C \/ 2,16 kg to ISO 1133-1. This is the sharpest single screen for recycled or degraded feedstock.<\/li>\nMelt flow rate of the pipe: 30 % maximum difference<\/strong> compared with compound from the same batch. This is the clause that catches over-processing \u2014 the resin can be fine and the extrusion still cooked it.<\/li>\nImpact resistance \u2264 10 %<\/strong>, tested at 0 \u00b0C for PP-R on 10 test pieces to ISO 9854-1 and ISO 9854-2.<\/li>\n<\/ul>\nThat last line is where Amendment 2:2022 changed things. The amendment adds a dedicated subclause 7.2 and splits impact testing by size: the Charpy method (ISO 9854-1 \/ ISO 9854-2) for DN \u2264 25 mm, and the round-the-clock method to ISO 3127 with a true impact rate TIR \u2264 10 % for DN \u2265 32 mm, both at 0 \u00b0C. <\/p>\n
If you import into a cold market, this is the requirement that matters on arrival, and it is new enough that asking which method was used is a fair test of whether a supplier reads the standards they print on the pipe.<\/p>\n
IFANULTRA’s own documented incoming and outgoing check sequence tracks this list rather than replacing it: resin grade verified by source and grade, a caliper wall check sampled across multiple pallets rather than the top layer only, OD and wall checked to ISO 15874 and DIN 8077, pressure and thermal testing to the rated class, and printed markings reconciled against certificate numbers. <\/p>\n
The sampling detail is the one worth copying into your own inspection brief \u2014 top-layer-only sampling is how a mixed pallet passes, and the mechanics of running that check on an arriving container are covered in PPR pipe batch consistency and incoming inspection<\/a>.<\/p>\nMarking and certification: what must be on the pipe<\/h2>\n Marking is the cheapest conformity check in existence and the one most often skipped. ISO 15874-2 clause 10.2 and its Table 12 set a minimum required marking list of eight items. Everything else on the pipe is the manufacturer’s choice; these are not.<\/p>\n
\n\n\nRequired aspect<\/th>\n Marking or symbol<\/th>\n<\/tr>\n<\/thead>\n \n\nNumber of the International Standard<\/td>\n ISO 15874<\/td>\n<\/tr>\n \nManufacturer’s name and\/or trade mark<\/td>\n Name or code<\/td>\n<\/tr>\n \nNominal outside diameter and nominal wall thickness<\/td>\n e.g. 16 \u00d7 2,2<\/td>\n<\/tr>\n \nPipe dimension class<\/td>\n e.g. A<\/td>\n<\/tr>\n \nMaterial<\/td>\n e.g. PP-R<\/td>\n<\/tr>\n \nApplication class combined with operating pressure<\/td>\n e.g. Class 1\/10 bar<\/td>\n<\/tr>\n \nOpacity (if declared by the manufacturer)<\/td>\n e.g. opaque<\/td>\n<\/tr>\n \nManufacturer’s information (traceability)<\/td>\n Production period \u2014 year and month, in figures or code; plus a name or code for the production site if the manufacturer produces at different sites<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nLook at the sixth row again. “Application class combined with operating pressure \u2014 e.g. Class 1\/10 bar.”<\/strong> The standard’s own example of how a PPR pipe should be marked contains no PN number at all. If a pipe is printed “PN20” and nothing else, it is not carrying the marking ISO 15874-2 requires. That does not make it bad pipe, but it does mean the print cannot be reconciled to a service class, which is precisely the reconciliation an inspector performs.<\/p>\n
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