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Yancheng Longwan Machinery Co., Ltd. HOME / PRODUCTS & APPLICATION / Ductile Cast Iron / Ductile Cast Iron Valve Accessories

Ductile Cast Iron Valve Accessories Foundry

Ductile Cast Iron Valve Accessories specializes in providing a range of valve accessories carefully manufactured from high-quality ductile iron. Ductile iron, as an advanced material that combines high strength, high toughness and good corrosion resistance, is an ideal choice for manufacturing key valve components. You can find a variety of key accessories designed specifically for valve systems, such as the valve body, which is the core component of the valve and is responsible for carrying fluid pressure and controlling its flow; and the box - used to protect the internal mechanism and provide a stable installation foundation. These accessories not only have good mechanical properties and can withstand long-term operation under high pressure, high temperature and harsh working environment, but also through precise manufacturing processes and strict quality control, they ensure the sealing, stability and reliability of the valve system.

Ductile Cast Iron Valve Accessories OEM/ODM
ABOUT US
Yancheng Longwan Machinery Co., Ltd.
Yancheng Longwan Machinery Co., Ltd.
Founded in 2006, which located next to National Highway 204 in Yancheng City, Jiangsu Province, 40km from the center of Yancheng City, 5km from the center of Dongtai City, 30km from Dafeng District, and 10km from the exit of Baiju Expressway, with convenient transportation. We mainly produce various types of fire-fighting pipe fittings, reducer parts, auto parts, agricultural machinery, and industrial robot parts. Its main customers include SAIC Group, Deere, Bonfiglioli (China), Shanghai Beixu, Yaskawa Electric, etc. As a famous China Ductile Cast Iron Valve Accessories Foundry and Ductile Cast Iron Valve Accessories Suppliers, our company has a variety of molding equipment, including one vertical sand-shot horizontal parting boxless shot-press molding line with specifications of 610*510*240, 120 boxes/hour, suitable for mass production of small parts; one upper and lower sand-shot horizontal parting boxless shot-press molding line with specifications of 750*650*250, 100 boxes/hour, suitable for mass production of small and medium-sized parts; 3 sets of 1.25T medium-frequency electric furnaces; 3 cleaning shot blasting machines, and now planning a lost foam production line, suitable for 100Kg~1000Kg casting production, and planning an automatic spray painting line and an electrophoretic coating line at the same time, 3 CNC lathes and 3 lathes.
Yancheng Longwan Machinery Co., Ltd.

ODM Customization Expert

Advanced Production & Processing Equipment

Longwan Machinery has a variety of advanced domestic and foreign molding equipment, including 2 fully automatic production lines for clay sand, 1 semi-automatic production line for clay sand, and 1 coated sand production line, with an annual production capacity of 15,000 tons.

Yancheng Longwan Machinery Co., Ltd.

Complete Inspection Flow

Strict Quality Inspection

We have full-process testing equipment: spectrum analyzer, metallographic microscope, universal tensile testing machine, magnetic particle flaw detector, ultrasonic flaw detector, etc.
The above equipment can fully ensure that we can provide customers with high-precision final castings, and at the same time ensure that we meet customers' comprehensive testing requirements for physical and chemical properties of materials, non-destructive testing, high-precision geometric dimension testing, etc.

Professional Casting Expert

Comprehensive Casting Manufacturer

FAQ
  • Q
    Where are your products mainly exported to?
    A

    Our products are mainly exported to multiple countries such as Germany, Japan, Italy, South Korea, and Australia.
  • Q
    How to deliver the goods to us?
    A

    Usually, we ship by sea, which is very convenient for export.

    Of course, if the customer's goods are urgent, we can also air freight them. Ningbo Airport and Shanghai International Airport are both very close to us.
  • Q
    What's the payment term?
    A

    When quoting, we will confirm the transaction method with you.

    For mass production, we usually make a 50% advance payment in advance and then inspect and confirm the shipment before paying the remaining balance.
  • Q
    How to guarantee the quality of your goods?
    A

    Firstly, there will be corresponding inspections after each process, and for the final completed product, we will conduct a full inspection according to customer requirements and international standards;

    Then, we have advanced and complete top testing equipment in the industry: spectral analyzers, metallographic microscopes, universal tensile testing machines, magnetic particle testing machines, ultrasonic testing machines, etc.

    The above equipment can fully ensure the provision of high-precision final castings to customers, while also meeting the comprehensive testing requirements of customers for material physical and chemical properties, non-destructive testing, high-precision geometric dimension testing, and so on.
  • Q
    How many employees of your company? what about the technicists?
    A

    Our company has more than 120 employees, including 10 professional technicians and 5 engineers.
  • Q
    How about the capacity of your company?
    A

    We have 2 fully automatic clay sand production lines, 1 semi-automatic clay sand production line, and 1 coated sand production line, with an annual production capacity of 15000 tons.
  • Q
    Do you have some standard parts?
    A

    No, currently we produce and customize according to the requirements based on the drawings provided by the customer.
  • Q
    Can you do customized products?
    A

    Yes, we are mainly doing customized products according to the customers’ drawings or samples.
  • Q
    What applications do your products relate to?
    A

    Our products cover almost all the applicable equipment manufacturing and machinery manufacturing and processing fields, mainly including automotive trucks, engineering machinery, agricultural machinery, reducers, water pumps, water treatment systems, and other fields.
  • Q
    what products can you offer?
    A

    We mainly produce cast iron parts made of gray cast iron and ductile iron materials.
  • Q
    Are you a direct manufacturer or trading company?
    A

    We are a foundry and a manufacturer of cast iron parts.
  • Q
    How long can I get the feedbacks after we sent the inquiry?
    A

    We will reply to you within 24 hours of the working day.
NEWS
Ductile Cast Iron Valve Accessories Industry knowledge

Yancheng Longwan Machinery Co., Ltd. casts and machines Ductile Cast Iron Valve Accessories manufacturer at our foundry in Yancheng City, Jiangsu Province. The range covers pressure-containing and structural valve components — bodies, bonnets, boxes, seats, discs and actuator housings — produced to customer drawings or samples rather than from a standard catalogue. Every project starts from the drawing, the pressure class, the machining scope and the annual volume we are asked to support.

Because the parts sit inside a valve assembly, we treat sealing faces, bore alignment, wall soundness and coating as one manufacturing problem, not separate operations. Casting, shot blasting, machining and final inspection are coordinated on the same site, which keeps dimensional responsibility in one place.

Our Ductile Cast Iron Valve Accessories Range

Valve bodies

The pressure-containing shell that carries fluid and controls flow. We cast bodies with the wall thickness, flange profile and port layout defined on your drawing, then machine gasket faces, bolt circles and bores from established datums.

Bonnets and covers

Bonnet castings house the stem and hold the pressure-tight joint at the top of the valve. Stem bore position, gland face flatness and bolting pattern are the features we machine and check most closely.

Valve boxes and mounting castings

Boxes protect the internal mechanism and provide a stable installation foundation for above-ground and buried service. Cast-in ribs, ears and lugs follow the customer's envelope and interface drawing.

Seats and discs

Seat and disc castings form the sealing pair. Ductile iron's wear resistance and elongation suit repeated open-close cycles, and the sealing surfaces are machined to the tolerance class agreed at drawing approval.

Actuator housings and brackets

Housings that convert a control signal into valve movement, plus the mounting adaptors that tie an actuator to a body. Impact and fatigue resistance matter more here than on static components.

Glands, retainers and miscellaneous hardware

Small machined accessories — glands, packing retainers, stemside fittings and handwheel hubs — are produced on the same lines and batched with the parent casting when volumes allow.

Component Fit, Function and Supply Scope

Component Role in the valve Design emphasis Supply condition
Valve body Contains pressure, routes flow Section soundness, wall consistency, flange flatness Cast + machined, blasted, coated
Bonnet / cover Stem housing, upper pressure joint Stem bore alignment, gland face finish Cast + machined
Box / mounting casting Protects mechanism, sets installation base Rib stiffness, thread and bore integrity Cast, partially or fully machined
Seat / disc Sealing pair, throttling contact Wear resistance, sealing surface tolerance Machined to drawing
Actuator housing / adaptor Transmits operating motion Impact and fatigue resistance, mounting accuracy Cast + machined
Gland / retainer Compresses packing, seals stem Flatness, concentricity, corrosion allowance Machined

Material Behaviour in Valve Service

Ductile iron carries graphite as spheroidal nodules instead of flakes. That structure is why we recommend it for pressure-retaining and impact-loaded valve parts: it delivers higher tensile strength and usable elongation than grey iron, so a body or bonnet deforms before it fractures when it meets a pressure surge or a handling impact.

  • Impact and fatigue tolerance for parts cycled repeatedly by the actuator.
  • Corrosion performance that suits water, wastewater and fire-protection circuits.
  • Fluidity that allows complex internal passages, ribs and bosses to be cast in one piece.
  • Machinability that keeps seat and gland tolerances repeatable in production batches.

Where a part needs stiffness and vibration damping more than elongation, Grey Cast Iron Valve Accessories are the practical alternative, and both material families are cast in the same plant. The exact grade, section and machining allowance are confirmed against your drawing before pattern making, and material condition is verified by chemical and mechanical testing rather than assumed.

Casting, Machining and Capacity Behind the Range

Yancheng Longwan Machinery operates clay sand and coated sand moulding, medium-frequency melting, shot blasting and in-house turning. That combination lets us hold one production route for a valve family from first article through repeat orders. Our moulding lines are matched to part size rather than to a single product type.

Equipment Specification Best fit
Vertical sand-shot horizontal parting boxless line 610 × 510 × 240 mm, 120 boxes/hour High-volume small valve accessories
Upper/lower sand-shot horizontal parting boxless line 750 × 650 × 250 mm, 100 boxes/hour Small and medium valve bodies, bonnets, boxes
Clay sand lines 2 fully automatic, 1 semi-automatic; 1 coated sand line Mixed order sizes, cores and complex contours
Melting 3 × 1.25 T medium-frequency electric furnaces Chemistry control across shifted batches
Cleaning 3 shot blasting machines Surface preparation before machining and coating
Machining 3 CNC lathes, 3 lathes Flange faces, bores, threads, seat pockets

Annual casting capacity is 15,000 tons. A lost foam line for 100 kg to 1000 kg castings is under development, together with automatic spray painting and electrophoretic coating capacity — relevant when a valve accessory programme calls for heavier bodies or a controlled surface finish.

Quality Control and Acceptance

Inspection is built into the route rather than added at the end. Each process step carries its own check, and finished valve accessories are fully inspected before shipment against customer requirements and the referenced standard. Our system follows IATF 16949:2016, which shapes how we control material, process changes and traceability.

  • German SPECTRO direct-reading spectrometer for chemistry verification.
  • Universal tensile testing machine and 3T Brinell hardness tester for mechanical properties.
  • Metallographic microscope and sonic velocity meter for graphite form and nodularity assessment.
  • Magnetic particle and ultrasonic flaw detection for surface and internal soundness.
  • Sand laboratory: SAC hammer-type sample making machine, SWY hydraulic strength testing machine, SSZ vibration-type sand screening machine, SGS double-disc infrared dryer.
  • High-precision geometric dimension checks on machined interfaces.

Acceptance scope — dimensional report, material certificate, NDT extent, pressure test responsibility and first-article approval — is agreed at the quotation stage so the release criteria are known before the first casting is poured.

ODM/OEM Configuration and Development Sequence

We supply to drawing or sample. There is no standard valve accessory catalogue, so the development sequence is deliberately short and controlled: drawings or samples received and confirmed, quotation issued, patterns and moulds produced, sample castings made and submitted for approval, mass production released only after that approval.

1. Drawing and sample review, quotation
2. Pattern and mould manufacture
3. Sample casting and customer confirmation
4. Mass production after release
5. Final inspection, jointly if requested
6. Packing and shipment

Packaging, colour and marking can be adapted to your requirements, and our design team reviews casting process plans against simulation results before patterns are cut, which shortens the development cycle for new valve bodies and reduces trial scrap. Ductile iron valve accessories often ship alongside our Ductile iron Pipe Fittings when a fire-protection or water-system package is ordered together.

Machining Interfaces, Installation and Serviceability

Valve accessories are supplied in the finish state your assembly line expects: as-cast, blasted, partially machined or fully machined with flanges faced and drilled, bores turned and threads cut. Critical features are referenced from datums defined on the drawing so that a bonnet, seat or gland mates correctly with parts produced in later batches.

  • Flange and gasket faces machined for a defined seal contact.
  • Stem bores and seat pockets turned to maintain concentricity across the assembly.
  • Threaded ports, screwed glands and actuator mounting holes produced to drawing callout.
  • Coating options to match the corrosion class of the installed environment.
  • Cast or stamped identification for traceability and spares matching.

Because the parts are cast and machined to a fixed drawing, replacement bodies, bonnets and seats can be re-ordered as repeat batches using retained patterns — useful for aftermarket valve spares and for maintenance programmes on installed water, firefighting and process equipment.

Information We Use to Configure Your Solution

Our quotation is built from the working point, the material grade and the production target, so the more of the following we receive, the more precisely the casting process, pattern layout and machining scope can be fixed.

  • 2D drawings or 3D models, or a physical sample for reverse quoting.
  • Material grade and any governing standard, plus hardness or microstructure requirements.
  • Casting weight, envelope size and the interface dimensions that must be machined.
  • Pressure rating, media and service temperature the part will see.
  • Annual volume, batch size and first-order quantity.
  • Machining scope, surface finish and coating or plating specification.
  • Inspection and NDT level, plus any requirement for joint inspection.
  • Marking, packaging, labelling and delivery destination.

Inquiries sent to us receive a reply within 24 hours of a working day, and our Ductile Cast Iron programme covers valve parts alongside automotive, agricultural, reducer, pump and robot components, so similar geometry and material requirements can be grouped in one production plan.

Frequently Asked Questions

Which valve components do you cast in ductile iron?

Bodies, bonnets and covers, boxes and mounting castings, seats and discs, actuator housings and adaptors, glands, packing retainers and small machined hardware. All are produced to the customer's drawing or sample.

Do you supply standard valve accessories from stock?

No. We custom produce according to drawings or samples, including pattern manufacture, first-article samples and repeat production batches. This keeps the part matched to your valve design rather than adapted from a general range.

How do you confirm the material before shipment?

Chemistry is verified on a German SPECTRO direct-reading spectrometer, mechanical properties on a tensile testing machine and a 3T Brinell hardness tester, and graphite form on a metallographic microscope. Sonic velocity measurement and magnetic particle or ultrasonic flaw detection are applied where the acceptance scope calls for them.

What capacity is available for a valve accessor

y programme?

Annual casting capacity is 15,000 tons, with two automatic clay sand lines, one semi-automatic clay sand line and one coated sand line. The 610 × 510 × 240 mm line runs at 120 boxes per hour for small parts and the 750 × 650 × 250 mm line at 100 boxes per hour for small and medium parts.

Can you machine and coat the castings as well as cast them?

Yes. We machine flange faces, bores, seat pockets and threads on CNC and centre lathes, and shot blast before machining and coating. Automatic spray painting and electrophoretic coating lines are being added to extend the available surface finishes.

How are valve accessories packed and delivered?

Packing and marking follow the agreed specification, and shipment is normally by sea, with air freight used when a customer's programme is urgent. Ningbo and Shanghai airports and Shanghai port are within convenient reach of our plant in Yancheng.