Bellows Sealed Globe Valve Body

Specifications

Key features

• Bonnet and body cast as one piece or split at the customer’s design, eliminating a potential fugitive emission path at the body-bonnet joint.
• Seat bore machined in a single setup with the stem guide to hold coaxiality within 0.05 mm, protecting bellows cycle life.
• Bellows weld neck pad machined to a controlled surface roughness to suit automatic orbital TIG welding of the bellows cartridge.
• Wall thickness verified by ultrasonic survey across the pressure boundary, with extra stock retained at high-stress fillet radii.
• CF8C and CF3M grades available for elevated temperature and low-carbon weld service respectively, with ferrite number controlled on duplex options.
• Investment cast flow passage with smooth internal contour, reducing pressure drop and turbulent erosion versus sand cast equivalents.
• Near-net-shape bosses, drain taps and nameplate pads cast in, cutting weld build-up and post-weld heat treatment.

Applications

• Steam and condensate service in refineries and chemical plants where zero stem leakage is mandated.
• Toxic, carcinogenic or volatile organic fluid transfer lines under fugitive emission control programs.
• High purity steam and thermal oil circuits in pharmaceutical and fine chemical production.
• Cryogenic and low temperature transfer lines when supplied in CF3M or CF8 with impact testing.
• Power plant auxiliary steam, feedwater bypass and boiler blowdown systems.
• Marine cargo and ballast piping systems with chlorine exposure, in duplex or super duplex grades.

Quality & compliance

We produce every bellows sealed globe valve body inside an IATF 16949 controlled process flow, with documented process control plans, first article inspection and statistical monitoring of critical seat and stem bore dimensions. We issue material certification to EN 10204 3.1 as standard, with 3.2 certification witnessed by a customer nominated or independent third party inspector available on request. Pressure boundary design margins follow the customer’s ASME B16.34 design basis, and hydrostatic shell testing plus seat leakage testing are performed to the customer’s or a third party’s written procedure, with signed test reports retained against heat lot records.

Non-destructive examination options include radiographic testing of casting critical areas, ultrasonic thickness and flaw survey, magnetic particle inspection per ASTM E709 and liquid penetrant inspection per ASTM E165. Positive material identification is carried out by handheld XRF on all alloy parts, and full heat lot traceability links each finished body to its melt record, heat treatment chart, NDT results and dimensional report. Ningbo Ruican does not hold or claim API, CE or PED certification as a company certificate; all compliance is supplied to the customer’s specification with documented objective evidence.

FAQ

Q1. Can you cast and machine the body to our existing bellows valve drawing without modification?
Yes. Send your drawing with tolerances, surface finish callouts and NDT level, and we will quote to print. If a feature is difficult to cast we will propose a near-net-shape alternative plus a machining allowance, we make but no geometry changes without your written approval.

Q2. Do you supply the bellows cartridge itself?
We supply the cast and machined valve body and bonnet. Bellows assembly welding, stem fitting and final valve assembly can be handled by your line or by a partner we introduce, and we will machine the weld pad to suit the cartridge supplier’s specification.

Q3. Which stainless grade do you recommend for high temperature steam?
CF8C is our usual recommendation for sustained elevated temperature service because of its niobium stabilization. For corrosive chloride environments we would suggest CF3M or ASTM A995 4A duplex, depending on the design temperature and pressure class.

Q4. What level of NDT do you provide and can we witness it?
Radiographic, ultrasonic, magnetic particle and dye penetrant inspection are all available, performed to written procedures and reported per casting. Customer or third party witness inspection can be arranged, and we can supply the raw film or digital records with the shipment package.

Q5. How is the seat leakage performance assured?
We machine the seat and disc seating surfaces to your specified finish and angle, then verify contact with a blue check or lapping gauge. Final hydrostatic and seat leakage testing follows your written procedure or that of your nominated third party, with certified results.

Casting process

Q6. What are your typical lead times and minimum quantities?
Tooling for a new wax die takes roughly four to five weeks, then sample parts follow in about three weeks and production runs typically four to six weeks. We accept prototype quantities from a single piece through to repeat production volumes, with no rigid minimum order.