{
  "company": "Hebei Yajiada Import and Export Co., LTD",
  "url": "https://hbyagada.com",
  "updated": "2026-07-28",
  "source": "https://hbyagada.com/blog and product pages",
  "faqs": [
    {
      "q": "What types of flanges do you manufacture?",
      "a": "Six flange types: Weld Neck (WN), Slip-On (SO), Plate Flat-Weld (PL), Socket-Weld (SW), Threaded (Th), and Blind (BL). All conform to ASME B16.5 / B16.47, EN 1092-1, JIS B2220, GOST, ISIRI 9117, and HG/T 20592.",
      "category": "company"
    },
    {
      "q": "What is the largest flange size and pressure class you supply?",
      "a": "NPS 1/2\" through NPS 60\", ASME Class 150 through Class 2500. EN PN 6 through PN 400.",
      "category": "company"
    },
    {
      "q": "Do you supply materials for low-temperature cryogenic service?",
      "a": "Yes. 16MnDR low-temperature steel (-46°C Charpy impact certified) per GB 150 / EN 13480. Supplied to Yamal LNG, QatarEnergy, and South Pars. A350 LF2 also available down to -46°C per ASME B16.5.",
      "category": "company"
    },
    {
      "q": "What is the minimum order quantity?",
      "a": "Typically 1 ton per size / spec. Full containers for export shipments.",
      "category": "company"
    },
    {
      "q": "Which certifications do you hold?",
      "a": "ISO 9001:2015 (since 2013), PED 2014/68/EU Module H (CE-marked, since 2017), ISIRI 9117 (Iran), NACE MR0175 sour service, EAC TR CU 032/2013 (Eurasian Customs Union). Mill Test Certificates per EN 10204 3.1 standard with every shipment.",
      "category": "company"
    },
    {
      "q": "Can you manufacture to custom drawings?",
      "a": "Yes. We accept drawings in PDF, DWG, STEP, and IGES formats. Custom non-standard flanges are quoted case-by-case with engineering review.",
      "category": "company"
    },
    {
      "q": "What materials can you source?",
      "a": "Carbon steel (A105, A350 LF2), stainless steel (304, 316, 316L), low-temperature alloys (16MnDR), Cr-Mo alloys (A182 F11 / F22), and duplex (F51 / F55) on request.",
      "category": "company"
    },
    {
      "q": "What is the typical lead time?",
      "a": "25–45 days from PO depending on specification and quantity. Mill run + heat treatment + NDT + machining + shipping.",
      "category": "company"
    },
    {
      "q": "What is the pressure equivalent of ASME Class 150 in EN 1092-1 PN rating?",
      "a": "ASME Class 150 ≈ EN PN 20 (both rated 285 PSI / 20 bar at room temperature). ASME Class 300 ≈ PN 50 (740 PSI / 50 bar). Class 600 ≈ PN 100 (1,480 PSI / 100 bar). Class 1500 ≈ PN 250 (3,625 PSI / 250 bar). These are nominal ratings; actual allowable pressure decreases with rising temperature per ASME B16.5 Table 2-1.1 and EN 1092-1 Table 9.",
      "category": "standards"
    },
    {
      "q": "Can ASME B16.5 and EN 1092-1 flanges be mixed on the same pipeline?",
      "a": "Mixing is allowed but requires matching bolt pattern and sealing face geometry. For most Class 150/PN 20 the bolt patterns align, but for higher classes they diverge. ASME uses larger bolt circles (inch-based) while EN uses metric. Always consult the cross-reference table before mixing. We have a Spec Sheet PDF for this comparison available on request.",
      "category": "standards"
    },
    {
      "q": "Which standard do Middle East EPC projects prefer?",
      "a": "Iranian EPC projects typically specify ISIRI 9117 (which is technically based on ASME B16.5 dimensions). Saudi Aramco projects use ASME B16.5. UAE ADNOC accepts both. Most Turkish EPCs specify EN 1092-1. For multi-region EPCs, dual-stamped flanges (ASME + EN) are available at 15-20% cost premium.",
      "category": "regional"
    },
    {
      "q": "What is the difference between NACE MR0175 and ISO 15156?",
      "a": "ISO 15156 is the international standard adopted in 2003 by 23 countries including the US. It is technically identical to NACE MR0175. NACE was rebranded as NACE International / AMPP in 2021. Specifying \"NACE MR0175 compliant\" remains common in the industry. Both documents cover sulfide stress cracking (SSC), hydrogen-induced cracking (HIC), and stress-oriented hydrogen-induced cracking (SOHIC) in oilfield equipment.",
      "category": "certification"
    },
    {
      "q": "Is A105 carbon steel NACE MR0175 compliant?",
      "a": "Yes, for limited conditions. A105 is acceptable for sour service per NACE MR0175 Part 1 provided hardness is ≤ 22 HRC (Rockwell C) and the material is in the normalized condition. For downhole or higher-stress components, A350 LF2 (also ≤ 22 HRC) is preferred due to its lower-temperature impact toughness. Above 22 HRC, A105 is not acceptable regardless of heat treatment.",
      "category": "certification"
    },
    {
      "q": "What about 316/316L stainless steel for sour service?",
      "a": "316 and 316L are accepted by NACE MR0175 Part 2 for chloride-containing sour environments up to a maximum temperature depending on H₂S partial pressure and chloride concentration. For severe conditions (high H₂S, high chloride), duplex F51/F55 or super duplex F53/F55 are required. Always specify both the chloride limit and H₂S partial pressure when ordering.",
      "category": "certification"
    },
    {
      "q": "What is ISIRI 9117?",
      "a": "ISIRI 9117 is the Iran Standard for pipe flanges, published by the Institute of Standards and Industrial Research of Iran. It is technically based on ASME B16.5 dimensions but adds additional Iranian-specific requirements including marking in both English and Persian numerals, third-party inspection certification by Iran-approved agencies, and customs declaration requirements.",
      "category": "regional"
    },
    {
      "q": "Do I need ISIRI 9117 marking if I export to Iran?",
      "a": "Yes, for customs clearance and many Iranian EPC projects. ISIRI 9117 specifies that the flange body must be permanently marked with the standard designation \"ISIRI 9117\", the pressure class, the size in NPS, and the manufacturer code. We supply all flanges to Iranian customers with ISIRI 9117 marking by default at no extra cost.",
      "category": "regional"
    },
    {
      "q": "How long does Iran customs clearance take with proper documentation?",
      "a": "For shipments with complete documentation (commercial invoice, packing list, MTC 3.1, ISIRI marking, third-party inspection cert when required, Bill of Lading), Iran customs clearance at Bandar Abbas typically takes 5-10 working days. Without proper ISIRI 9117 documentation, shipments may be held for 4-6 weeks or rejected.",
      "category": "regional"
    },
    {
      "q": "What is the lowest service temperature for 16MnDR?",
      "a": "16MnDR is qualified for -46°C service per GB 150-2011 and EN 13480. Charpy V-notch impact testing at -46°C must show ≥ 27 J average per specimen (≥ 21 J individual). For LNG service, this matches the design temperature of the largest LNG terminals (Qatar, Yamal, Sabine Pass).",
      "category": "cryogenic"
    },
    {
      "q": "Is 16MnDR equivalent to A350 LF2 for LNG service?",
      "a": "For LNG service (-46°C), both 16MnDR (GB) and A350 LF2 (ASME) are accepted. A350 LF2 is the ASME designation; 16MnDR is the Chinese GB designation with equivalent mechanical and impact properties at -46°C. In practice, 16MnDR is ~10-15% cheaper than A350 LF2 due to lower material cost in China.",
      "category": "cryogenic"
    },
    {
      "q": "Can 304/316L stainless be used for LNG?",
      "a": "Yes, austenitic stainless steels (304L, 316L) are commonly used for LNG piping down to -196°C without issue. Their austenitic structure does not undergo the ductile-to-brittle transition that affects ferritic steels. For LNG flanges specifically, 16MnDR or A350 LF2 is more common for cost reasons, while 304L/316L is used for cryogenic pump and valve bodies.",
      "category": "cryogenic"
    },
    {
      "q": "Which facing type should I use for high-pressure service?",
      "a": "RTJ (Ring Type Joint) for Class 600 and above in hydrocarbon service. The metal ring gasket is compressed into machined grooves, providing a self-energizing seal that improves with pressure. RF (Raised Face) with spiral-wound gasket is acceptable to Class 600. FF (Flat Face) only for low-pressure Class 150 service or where mating flange is non-metallic.",
      "category": "facing-types"
    },
    {
      "q": "Can I mix RF and FF flanges?",
      "a": "No. RF flanges have a 1/16\" or 1/4\" raised face above the bolt circle, while FF flanges are flat. Bolt hole patterns are usually compatible, but the gasket seating geometry is not. Forcing RF against FF will damage the raised face and cause leakage. Always match facing types when joining flanges.",
      "category": "facing-types"
    },
    {
      "q": "What is the standard surface finish for RF flanges?",
      "a": "125-250 micro-inches Ra (3-6 μm) serrated finish per ASME B16.5 §6.4.3. This roughness is achieved by concentric or helical serration and is essential for proper gasket bite with spiral-wound or compressed non-asbestos gaskets. Smoother finishes (32-63 Ra) are used for soft gaskets in low-pressure service.",
      "category": "facing-types"
    },
    {
      "q": "When should I use ASME B16.47 instead of B16.5?",
      "a": "Use ASME B16.47 for flanges NPS 26\" and larger. B16.47 covers two series: Series A (MSS-SP-44 derived, generally larger bolt circles) and Series B (API 605 derived, smaller bolt circles). Series A is more common in North America, Series B in international markets. B16.5 ends at NPS 24\".",
      "category": "standards"
    },
    {
      "q": "Are Series A and Series B interchangeable?",
      "a": "No. While the pressure ratings are the same (Class 150, 300, 400, 600, 900), the bolt circle diameters differ. A Series A NPS 30 Class 150 flange has 36 bolts at 39.75\" bolt circle. Series B NPS 30 Class 150 has 28 bolts at 34.00\" bolt circle. Mixing them is dangerous and will cause immediate leak. Always specify which Series is required.",
      "category": "engineering"
    },
    {
      "q": "Which is cheaper: B16.5 or B16.47?",
      "a": "B16.47 large-bore flanges are typically 30-50% more expensive than equivalent B16.5 flanges of the same pressure class due to the larger material volume, heavier forging, and more bolt holes. For NPS >24, this cost premium is unavoidable.",
      "category": "size-specs"
    },
    {
      "q": "When should I specify forged instead of cast?",
      "a": "Specify forged flanges for all pressure classes above Class 300, all low-temperature service below -29°C, all sour-service (NACE) applications, and any cyclic-service condition. Cast flanges are acceptable for Class 150 and Class 300 utility service where cost is the primary driver. Forging refines the grain structure, eliminating porosity and improving mechanical properties.",
      "category": "manufacturing"
    },
    {
      "q": "How can I tell if a flange is forged or cast?",
      "a": "Visual: forged flanges have a smooth, fine-grained surface texture; cast flanges have a coarse, slightly rough surface with visible parting lines. Manufacturing: the flange is forged when the raw material is a forged bar or billet machined to shape; cast when molten metal is poured into a sand or investment mold. Per ASME B16.5, forged flanges are mandatory for all pressure classes above Class 250.",
      "category": "manufacturing"
    },
    {
      "q": "What is the cost difference?",
      "a": "Forged flanges are typically 40-80% more expensive than cast flanges of equivalent size and class. For Class 150 NPS 2\": forged ~$8-12/piece vs cast ~$4-6/piece. For Class 600 NPS 12\": forged ~$120-180/piece vs cast ~$60-100/piece. The cost difference increases with size and pressure class.",
      "category": "facing-types"
    },
    {
      "q": "Should I choose A105 or A350 LF2 for my project?",
      "a": "A105 for general-purpose ambient-temperature service above -29°C (carbon steel). A350 LF2 for low-temperature service down to -46°C (cryogenic, LNG, ammonia, CO₂). A350 LF2 has guaranteed Charpy V-notch impact testing at -46°C while A105 has no low-temperature guarantee. Cost difference is typically 15-25% premium for LF2.",
      "category": "material"
    },
    {
      "q": "Is A105 suitable for sour service (NACE MR0175)?",
      "a": "Yes, A105 is NACE MR0175 compliant for many sour-service applications, but ONLY when hardness is ≤ 22 HRC. If the A105 has been cold-worked or improperly heat-treated, hardness may exceed 22 HRC and the material will fail NACE compliance. Specify hardness testing on MTC for any A105 sour-service order.",
      "category": "certification"
    },
    {
      "q": "Can A105 and A350 LF2 be welded together?",
      "a": "Yes, both are carbon-manganese steels with similar weldability. Preheat to 150-200°C for both. Post-weld heat treatment (PWHT) is generally not required for A105/A350 LF2 below 19mm thickness, but is mandatory above 19mm per ASME B31.3 §330.1. Use E7018 or E6010 electrodes with matching mechanical properties.",
      "category": "material"
    },
    {
      "q": "What is the difference between ISO 9001 and PED 2014/68/EU?",
      "a": "ISO 9001 is a quality management system certification covering the manufacturer\\'s processes (production, inspection, traceability, document control). PED 2014/68/EU is the EU Pressure Equipment Directive, a regulatory requirement that CE-marks each pressure-bearing product sold in Europe. PED requires ISO 9001 as a base, plus material traceability, third-party inspection, and full technical documentation per PED Annex I.",
      "category": "facing-types"
    },
    {
      "q": "When do I need CE-marking?",
      "a": "CE-marking is mandatory for all pressure-bearing equipment sold in the EU above PED thresholds (Category I to IV depending on pressure, size, and fluid). For our products: any flange above PN 25 or used with Category I+ fluids (gas, steam, hazardous liquids) requires CE-marking. We provide PED Module H certification since 2017.",
      "category": "engineering"
    },
    {
      "q": "How long does ISIRI 9117 certification take?",
      "a": "ISIRI 9117 marking and third-party inspection certificate typically takes 7-10 working days per shipment. The manufacturer must be pre-registered with ISIRI and the inspector must be Iran-approved. We have pre-registered status since 2016, so our lead time is consistently 7 days for Iran orders.",
      "category": "regional"
    }
  ],
  "categories": {
    "company": "Company-level FAQs about capabilities, certifications, MOQ, lead time",
    "standards": "ASME / EN / JIS / GOST technical conversion and comparison",
    "certification": "NACE MR0175 / ISO 15156 / PED 2014/68/EU / MTC EN 10204",
    "regional": "Region-specific (Iran ISIRI 9117 / Middle East EPCs)",
    "cryogenic": "LNG / 16MnDR low-temperature service",
    "material": "Carbon / stainless / low-temp / Cr-Mo / duplex",
    "manufacturing": "Forging vs casting, process selection",
    "facing-types": "RF / FF / RTJ / T&G / M&F facing types",
    "size-specs": "B16.5 vs B16.47 large-bore selection",
    "engineering": "Other engineering references"
  }
}