What is the maximum size capability for butt-welding pipe cap?

Bends up to Φ2200 mm large diameter; pushed and pressed fittings up to DN1500 with 100 mm wall thickness; forged flanges up to Φ4000 mm; single-piece forging up to 50 tons. Exact capability is confirmed by drawing and material grade.

What inspection and quality documents are provided?

Standard package: EN 10204 3.1 material certificate, chemical analysis, mechanical test report, dimensional inspection report, NDT report (PT/MT/UT/RT as required), heat-treatment record, packing list. Third-party witness (SGS / BV / TÜV / Lloyd's) is available on request.

What is the typical lead time?

Standard fittings in common sizes: 15-30 days. Non-standard sizes or special materials: 30-60 days. Large-diameter pushed fittings and forged flanges: 45-90 days. Prefabricated piping spools depend on drawing complexity. Exact lead time is confirmed against current production schedule when the RFQ is received.

What certifications does Hebei Haihao hold?

ISO 9001 quality management, ISO 14001 environmental management, ISO 45001 occupational health & safety, ABS Type Approval for flanges and fittings, and a national manufacturing license for pressure-piping components. Full certificate images are available on the Certificates page.

What Incoterms and payment terms are supported?

We support FOB, CFR and CIF. Accepted payment: irrevocable L/C at sight only. Final terms are agreed per order value and ongoing relationship.

Butt-Welding Pipe Cap Manufacturer

Description

Hebei Haihao Group manufactures butt-welding pipe caps — also known as end caps, blind ends or dished heads — by hot pressing or stamping, welded onto pipe ends or threaded ends to close the line. Available in spherical, ellipsoidal, dished and flat geometries.

Applications

Oil & gas pipelines, refinery, petrochemical, power, chemical, pressure vessel ends, water supply and district heating.

Technical specs

Standards: ASME B16.9 / B16.28, MSS SP-75, EN 10253, GB/T 12459, GB 150. Material: ASTM A234 WPB; A403 WP304/WP316; A420 WPL6; carbon, alloy, stainless steel. Size range: 1/2" - 48" (DN15 - DN1200). Pressure / wall: Sch 10 - Sch XXS. NDT: visual + dimensional; RT/UT/PT/MT on request. Surface: shot-blasted, oiled or painted.

Referenced standards

ASTM A234

Standard title: Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service
Issuing body: ASTM International

Similar / alternate materials

This product covers multiple base grades. Alternates below are grouped by base family — each card is an upgrade path FROM the labeled base grade when service conditions move outside its envelope. Final selection must be reviewed by a qualified materials engineer.

From base：ASTM A234 WPBCarbon-steel family: ambient ~ 425°C; outside this band, switch to alloy or low-temp steel.

Upgrade paths

ASTM A234 WPB →ASTM A420 WPL6

Switch to A420 WPL6 when service temp ≤ -29°C (Charpy at -46°C); WPB is not qualified for low temperature.

ASTM A234 WPB →ASTM A234 WP11 / WP12

For creep range (~450-540°C) move to 1.25Cr-0.5Mo (WP11) or 1Cr-0.5Mo (WP12).

ASTM A234 WPB →ASTM A234 WP22

For high-temp creep / hydrogen service use 2.25Cr-1Mo (WP22), common in hydrotreaters and boiler reheat.

Typical industry applications

How procurement teams typically deploy this material/category in real projects. Compare against your project spec before locking the BOM.

Oil & Gas PipelinesOnshore crude / gas trunk lines: API 5L X42 and below pair with A234 WPB; X52-X70 must pair with MSS SP-75 WPHY-52/60/65/70 (yield-strength match). Service window -29 to +120°C (B31.4 / B31.8 onshore practice).
Water & Fire ProtectionMunicipal water, cooling-water loops, fire mains; carbon steel with galvanizing or epoxy lining.
LNG / CryogenicPropane / LPG (~-46°C) → A420 WPL6; ethylene (~-101°C) → A420 WPL3; LNG (-162°C) / liquid nitrogen (-196°C) butt-weld fittings step up to A420 WPL8 (Ni 8.4–9.6%, commonly called 9% Ni).
Chemical / Food / PharmaAcidic process / process water / CIP loops: A403 WP304L for ambient dilute acid, WP316L with Mo for chloride resistance (matching pipe to A312 is TP304L/TP316L).
OffshoreSeawater loops / FPSO process lines prefer duplex A815 WP-S31803 (2205) / super duplex A815 WP-S32750 (2507); 316L only for short-term or low-chloride sections (SCC risk above ~60°C even with 316L).

Standards and Materials

The following supports product selection and RFQ communication. Final requirements follow drawings, standards and purchase documents.

CategoryCap

Material / StandardASTM A234 WPB; A403 WP304/WP316; A420 WPL6; carbon, alloy, stainless steel

Size range1/2" - 48" (DN15 - DN1200)

Wall (Schedule)Sch 10 - Sch XXS

ScopeButt-welding pipe caps and dished heads to seal pipe ends in pressurized piping systems.

Frequently asked questions

What standards does Hebei Haihao manufacture butt-welding pipe cap to?

We produce to ASTM/ASME (A234 WPB / WPC / WP1 / WP11 / WP12 / WP22 / WP91; A403 stainless; A420 WPL6 low-temperature), EN (EN 10253 (Parts 1–4)), JIS (B2311 / B2312 / B2313), GB (GB/T 12459 / GB/T 13401) and MSS SP-75 high-strength low-alloy. Final material and standard are confirmed by drawing or RFQ.