About Us

ZHEJIANG CHENGJIU PIPELINE CO., LTD. (CNCJ)

Zhejiang Chengjiu Pipeline Co., Ltd. - operating under the brand name CNCJ - was established in 2012 in Quzhou, Zhejiang Province, China. We are a manufacturer of stainless steel flanges, carbon steel flanges, butt-weld pipe fittings, and industrial valves, with a registered capital of RMB 20 million.

Our product range covers flanges in sizes DN10 to DN5000 (½" to 80"), pressure ratings from 0.25 MPa to 42.0 MPa (150 lb to 2500 lb), and temperature resistance from -196°C to 1350°C. We produce to all major international standards including ANSI B16.5, EN 1092-1, DIN, GOST, JIS B2220, AS2129, AS4087, AWWA C207, MSS SP-44, and SABS/SANS 1123.

CNCJ holds ISO 9001:2015, ISO 14001, and ISO 45001 certifications. All products are supplied with material test certificates (MTC) to EN 10204 3.1 as standard. Our brand trademarks are registered in Malaysia and Vietnam.

2012

Year Established

13,000 m²

Factory Area

120+

CNC & NC Machines

50+

Production Staff

10,000 t/yr

Annual Output

30+

Export Countries

Manufacturing Capability

Forging Workshop

CNCJ operates its own in-house forging workshop, giving us direct control over the raw material forming process. Flange blanks are forged from certified round steel billets - no outsourced semi-finished products. In-house forging ensures consistent grain structure, dimensional accuracy, and full material traceability from billet to finished flange.

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CNC Machining

Our machining area operates more than 100 CNC and NC lathes across two zones: a large-bore turning zone for flanges DN500 and above, and a small-bore turning zone for DN10 to DN400. This dual-zone layout allows us to run large and small diameter orders simultaneously without scheduling conflicts, maintaining short lead times across the full size range.

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Drilling

Bolt hole drilling is performed on dedicated CNC drilling machines in both large and small drilling zones. Bolt circle diameter (PCD), hole count, and hole diameter are machined to the dimensional tolerances of the applicable standard - ANSI B16.5, EN 1092-1, GOST 33259, AS4087, or other project-specified standards. All drilling programs are verified against standard dimensional tables before production runs begin.

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QUALITY ASSURANCE

3-stage inspection on every flange: dimensional check, PMI material verification, and EN 10204 3.1 MTC as standard. ISO 9001:2015 certified.
GOOD SERVICE

Enquiries answered within 24 hours. Drawings, MTCs, and inspection reports provided upfront - no chasing required.
REASONABLE PRICE

Factory-direct pricing - no middlemen. In-house forging, machining, and drilling on 120+ CNC machines keeps costs controlled at every step.
FAST DELIVERY

Standard sizes ship in 2–4 weeks. Stock maintained across raw material, blanks, and finished goods for fast turnaround.

Quality Control

Flat Layout & Visual Inspection

In our dedicated QC area, all finished flanges are laid flat in ordered, separated layers using protective interleaving-never bulk-stacked or jumbled together. This standardized flat layout prevents metal-to-metal scratching and allows our inspectors to perform 100% surface quality and visual checks on every single piece. It also ensures flawless batch traceability before the final packaging sequence begins.

Dimensional Inspection

Every flange undergoes meticulous dimensional verification to ensure 100% compliance with international standards (ASME, EN, DIN, JIS, etc.). Thanks to the flat layout, inspectors have complete access to verify and record key parameters for every piece, including Outside Diameter (OD), Flange Thickness, Raised Face (RF) Height/Diameter, Bolt Circle Diameter (PCD), and Bolt Hole Alignment.

Material Verification (PMI Testing)

To eliminate any risk of material mix-ups, we conduct Positive Material Identification (PMI) testing right on the flat-laid products using advanced handheld spectrometers. This step verifies the exact chemical composition (such as Chromium, Nickel, and Molybdenum levels) of the finished flanges against specified material grades (e.g., SS304, SS316L). This on-site verification guarantees that the physical cargo matches its Material Test Certificate (MTC) with absolute certainty.

Packing, Warehouse & Global Delivery

Packing & Dispatch

Before shipment, each flange is marked with heat number, material grade, standard, pressure rating, and size. Products are cleaned and inspected for surface condition, then packed in wooden cases or on pallets with appropriate protection for sea freight. Export packing specifications can be customized to customer requirements, including desiccant, VCI film, or special crating for oversized flanges.

Warehouse

Our warehouse is divided into three dedicated zones: round steel stock (including PMI-tested certified billets), rough blanks awaiting machining, and finished goods ready for shipment. Maintaining stock across all three stages allows us to respond quickly to urgent orders and reduces lead time for standard specifications. Standard carbon steel and stainless steel grades (SS304, SS316L) in common sizes are typically available from finished goods stock.

Global Delivery

CNCJ exports to customers in more than 30 countries across five continents. Our nearest export port is Ningbo / Shanghai, with regular consolidated and full-container shipments to all major global destinations. We handle all export documentation including commercial invoice, packing list, bill of lading, certificate of origin, and MTC.

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