Baoding Guokun Casting is a professional ductile iron foundry, resin sand casting foundry and pipe fittings manufacturer located in Baoding, China. We specialize in custom ductile iron casting, supplying high-quality ductile iron split repair clamp, pipe repair sleeve, tapping saddle, pipe leak repair clamp and other ductile iron pipeline castings for global pipeline contractors, valve distributors and waterworks partners. As a trusted metal casting factory, we focus on resin sand casting process to produce pressure-bearing pipe fittings with stable quality, precise dimension and reliable pressure resistance.

Split repair clamp, also known as pipe repair sleeve, is a core ductile iron pipe fitting widely used for on-site pipeline leakage repair, emergency pipe crack fixing, saddle tapping and branch connection for water supply, drainage, gas and irrigation pipelines. Our ductile iron repair clamps fit ductile iron pipes, steel pipes, PE pipes, PVC pipes and HDPE pipes, supporting PN10, PN16 pressure grades. Compared with ordinary grey iron castings, ductile iron material combines high tensile strength and good elongation, anti-shock performance and crack resistance, which makes it the ideal material for pressure pipeline repair parts.

We mainly adopt EN-GJS-450-10 and EN-GJS-500-7 ductile iron for our split repair clamp castings, compliant with ISO 1083 and ASTM A536 standards. GJS-450-10 is the most popular grade for standard repair sleeves, balancing toughness and casting performance for most municipal water and gas projects. GJS-500-7 delivers higher tensile strength, suitable for heavy-duty, high-pressure underground pipeline working conditions. All ductile iron raw materials are strictly inspected before melting, and we provide material test certificates for every batch of ductile iron castings for our overseas customers.

No.	Process Step (EN)	Operation Detail
1	Pattern making	Make wooden or aluminum patterns and core boxes according to customer drawings. Patterns define the external shape and delivery dimensions of the ductile iron casting.
2	Sand mixing	Mix silica sand, furan resin and hardener uniformly in the sand mixer. The resin acts as the binder, the hardener controls curing speed.
3	Molding & coring / core setting	Fill the mixed resin sand into the pattern flask and core box to make the outer mould, and produce sand cores for internal cavities such as the valve body inner passage.
4	Self-hardening at room temperature	The sand mixture cures by chemical reaction at room temperature with no heating required. The mould gains enough strength after curing.
5	Mould assembling (closing mould)	Take out the pattern, place the sand core inside the mould cavity, then close and clamp the mould. Core position and gating system are checked before closing.
6	Melting & spheroidizing + inoculation treatment	Melt pig iron and scrap steel in the induction furnace, then carry out spheroidizing and inoculation treatment to obtain qualified QT450-10 / EN-GJS-450-10 ductile iron molten iron.
7	Pouring	Pour the molten ductile iron into the assembled mould cavity through the gating system, with controlled pouring temperature and speed to avoid turbulence and slag entrapment.
8	Cooling	Keep the casting inside the mould for a proper cooling period until the metal solidifies completely. Do not shake out too early.
9	Shakeout & sand removal	Break the sand mould and take out the rough casting; remove adhered sand from the casting surface and cut off runners and risers.
10	Shot blasting	Shot blast the rough casting to remove oxide scale, improve surface finish and reveal surface defects before inspection.
11	Stress relief annealing	Heat treatment to eliminate internal casting stress and avoid deformation or cracking during later machining and field service.
12	Rough & finish machining	CNC machining for flanges, sealing faces, holes and key grooves to meet drawing tolerances. Rough machining first, finish machining after stress relief.
13	Inspection & testing	Chemical composition test, mechanical property test, dimensional inspection, visual check, NDT and hydraulic pressure test for valve and pressure castings; material certificates issued per batch.
14	Packing & delivery	Qualified castings are packed with rust protection, wooden pallet or case, shipping marks, and arranged for shipment together with full documentation.

As a professional resin sand casting foundry, we choose resin sand casting (no-bake sand casting) for our ductile iron split repair clamp production, which brings obvious advantages for pipeline casting parts. The rigid resin sand mold has low deformation during pouring and solidification, delivering excellent dimensional accuracy, consistent wall thickness and smooth as-cast surface. This greatly reduces internal defects such as shrinkage porosity, air holes and slag inclusion, which is critical for pressure retaining pipe fittings. Resin sand casting also supports complex cavity structure for flange tapping saddle repair clamps, with clear casting marks and less machining allowance. Whether you need small batch prototype castings or bulk order pipe repair sleeves, our resin sand casting line can arrange flexible production and stable lead time. After casting, all ductile iron repair clamp blanks go through stress relief annealing treatment to eliminate internal casting stress, preventing deformation in subsequent machining and field service. We carry out visual inspection, magnetic particle testing (MT) and hydrostatic pressure test for finished castings to guarantee zero leakage under rated working pressure.

As an experienced pipe fittings production factory, Baoding Guokun Casting supports OEM & ODM customization of ductile iron split repair clamp. We can produce straight repair clamp, socket repair clamp, flanged tapping saddle clamp, extended repair sleeve according to your drawings, samples or technical specifications.

Working with Baoding Guokun Casting, your company will gain multiple benefits: direct factory price from the ductile iron casting factory, stable quality control by our in-house metallurgical and QC team, full set of inspection documents, flexible MOQ and reliable on-time shipment. We are not only a metal casting factory, but also your long-term technical partner for ductile iron pipeline casting solutions. Our engineering team can communicate casting feasibility, optimize structure design to lower your cost, and solve technical problems for your pipe repair clamp projects.

If you are sourcing reliable ductile iron split repair clamp, pipe repair sleeve, or looking for a stable resin sand casting foundry for your ductile iron pipe fittings, welcome to contact Baoding Guokun Casting. We are ready to provide casting samples, quotation and technical support for your pipeline projects.

A High Quality China Foundry！

Guokun Casting, of Baoding Hebei is an ISO 9001-2008 registered iron and steel foundry & supplier of high quality carbon steel, cast iron and machined castings used in power, mining, railway, agricultural, tillage, truck, automobile, pump, valve, motor, pipe fittings and gear industry.

With a montly capacity of 100,000kgs and with more than 25 years of experience ensure the short delivery and the highest valued iron & steel casting parts.

Baoding Guokun Machinery Co., Ltd.

Baoding Guokun Export and Import Trading Co., Ltd

Office Add: 777# Chaoyang South Street, Baoding City, Hebei, 071000, China

Factory Address: Wangdu County, Baoding City, Hebei, 071000, China

Website: www.metalcastingfactory.com

Tel: 86-312-5951319 Fax: 86-312-5951296

Phone: 86-181 3278 9710 (WhatsApp & WeChat)

Email: gina@guokuncasting.com