The EGR valve housing body sits in the exhaust gas recirculation path between the exhaust manifold and the intake tract. It carries the valve seat. It also carries the stem bore. This part also carries the actuator mounting flange and a coolant gallery that pulls heat out of the gas stream. Fabricated sheet or welded tube housings crack at the flange-to-body weld after a few thousand hot-cold cycles, and housings machined from solid bar or plate carry heavy material removal cost plus a cored coolant passage that has to be gun-drilled and plugged. Ningbo Ruican casts the housing as one body with the gas passage and coolant gallery produced by ceramic core, then finish machines the flange face, valve bore and stem guide in a single datumed setup so the seat stays concentric to the bore under thermal cycling.
Specifications
| Parameter | Specification |
|---|---|
| Casting process | Silica sol lost wax investment casting with ceramic core for the gas passage and coolant gallery; water glass route available for lower volume service parts |
| Material options | High-SiMo ductile iron (EN-GJS-SiMo45-6, SiMo 4.05 / 5.5 chemistry); ASTM A351 CF8C niobium-stabilised stainless; EN-GJS-500-7 offered for cooler inlet duty below 400 C |
| Dimensional tolerance (ISO 8062-3 CT grade) | CT6 as cast; CT5 after machining; CT4 held on the valve stem bore, seat and flange datum faces |
| Machining | 4-axis CNC milling of flange and actuator faces, CNC turning of the valve seat, boring of the stem bore, drilling and tapping of mounting holes |
| Surface finish (Ra) | Ra 3.2 um machined on the flange and actuator faces; Ra 1.6 um on the stem bore and seat; Ra 6.3 um shot blasted as-cast exterior |
| Weight range | 0.9 kg to 3.6 kg per housing depending on bore size and gallery length |
| Typical lead time | Tooling 5-6 weeks; first article 3-4 weeks after tooling; production 6-8 weeks |
Key features
- One-piece cast body replaces a fabricated assembly and removes three welds: flange-to-body, coolant spigot and actuator boss, together with the post-weld straightening operation.
- Ceramic-cored coolant gallery eliminates two gun-drilling operations and the press-fit plug and seal weld normally needed to close a drilled passage.
- High-SiMo ductile iron holds strength and oxidation resistance in continuous EGR gas duty up to about 760 C; CF8C extends the useful range to roughly 850 C.
- Valve stem bore machined to H7 with roundness within 0.03 mm, so the poppet or rotary valve stays free instead of sticking as carbon builds up on the guide.
- Flange face machined flat within 0.05 mm over 120 mm, removing the gasket leak path that appears on welded housings after repeated thermal cycles.
- Coolant gallery pressure tested at 4 bar and the gas path at 1.5 bar to the customer’s method, with results reported on the lot documentation.
- Silicon at 4.2-4.6 percent and molybdenum at 0.4-0.6 percent give the SiMo grade its thermal fatigue resistance, verified by spectrometer on every heat.
Applications
Typical applications include cooled EGR valve housings on light-duty and heavy-duty diesel engines. It also includes EGR cooler bypass valve bodies and changeover flap housings. It also includes exhaust throttle and back-pressure valve bodies for commercial vehicle aftertreatment. The part also includes gasoline engine low-pressure EGR valve bodies with integrated water jacket. It also includes stationary engine and genset EGR modules running long steady-state duty cycles. This scope also includes marine and off-highway diesel EGR housings exposed to salt-laden intake air.
Quality & compliance
Ningbo Ruican casts and machines to IATF 16949 and works to ISO 9001, issuing EN 10204 3.1 material certification with every shipment. PPAP Level 3 and FAIR packages are available on request, built from the customer’s ballooned drawing and submission template. Moreover, each heat is traceable from the melt record through heat treatment to the finished part. Also, every lot ships with a hardness survey, spectrometer chemistry results and a dimensional report covering all ballooned features. Pressure testing of the coolant gallery and gas path, thermal cycling and salt-spray exposure are performed to the customer’s drawing specification and acceptance criteria.
FAQ
Can you work from a sample EGR housing instead of a drawing?
Yes. Send an existing housing or a scrap return and we reverse scan it, produce a 3D model, and return the model together with a DFM review covering gating position, coring of the gallery and machining allowance. You approve the model before tooling is cut, and the scan data stays available for later engineering changes.
What is the minimum order quantity for a new housing program?
Tooling can be built for a pilot quantity as low as 20 to 50 pieces for validation builds, then production moves to multi-cavity tooling once volume justifies it. Typical annual programmes run from a few thousand to well over one hundred thousand pieces. Generally, we hold agreed safety stock against a released schedule.
Do you support PPAP submission?
We support PPAP Level 3 submission including the dimensional results report, material and performance test results, process flow diagram, control plan, PFMEA and process capability study on the characteristics you designate. Additionally, where your template differs, we populate your forms and add the supporting evidence they require.
Can you machine the housing fully in-house?
In general, all machining is done in-house on 3-axis, 4-axis and 5-axis CNC machines plus CNC turning. The casting never leaves our control plan. Fixtures are designed and built internally, which keeps the datums used for machining identical to those used for inspection and PPAP reporting.
Do you supply heat treatment?
We supply the SiMo and CF8C grades with the heat treatment condition the drawing calls for, including ferritising anneal, normalising, and stress relieving, with furnace charts included in the lot documentation. Also, hardness, microstructure and mechanical test results are reported. In addition, we can supply test bars for tensile verification where the drawing requires it.
CTA
Send your EGR valve housing drawing, sample or 3D model for a DFM review, coring proposal and a tooling plus piece price quotation. Contact Wendy She — sales@cnsandcasting.com — WhatsApp +86-13777124360, or visit https://cnsandcasting.com to start your program with Ningbo Ruican.
