Class Code 3634
Valve Mfg
Class Code 3634 covers employers who manufacture, machine, assemble, repair or test industrial valves. This classification applies to shops that perform metalworking operations, welding, heat treating and pressure testing. The approved pure premium rate for California effective September 1, 2026 is $2.758 per $100 of payroll.
What Class Code 3634 Covers
Class Code 3634 specifically describes businesses that produce and overhaul valves and valve components used in oil & gas, power generation, waterworks, chemical processing and HVAC systems. Covered operations include machining castings and forgings, welding and brazing valve bodies and stems, heat treating, seat lapping and hand-fitting, assembly of packing/glands/stems, nondestructive inspection, hydrostatic and pneumatic pressure testing, and surface finishing such as plating and painting. Both OEM valve manufacturers and independent repair/overhaul shops fall under this code when they perform hands-on metal fabrication, testing and final assembly. Shops that only sell valves without performing fabrication or testing would not be properly classified here. Integrated operations that also cast components may still use 3634 if the primary business is valve manufacture and assembly.
Who It Applies To
- OEM industrial valve manufacturers (gate, globe, ball, check, butterfly valves)
- Valve repair, overhaul and remanufacturing shops performing machining and testing
- Machine shops specializing in valve components and stem/seat machining
- Fabrication shops doing welding, brazing and assembly of valve bodies
- Quality control and testing technicians performing hydrostatic/pneumatic tests
- Inspectors performing NDT (dye penetrant, ultrasonic) on valve parts
Common Job Duties
- CNC turning, milling and grinding of valve bodies, bonnets and stems
- Welding, brazing and filler-metal work on valve components
- Heat treating and stress relieving of valve parts
- Assembling stems, packing, seats, gaskets and actuators
- Hydrostatic and pneumatic pressure testing and leak-checking
- Surface finishing: grinding, polishing, plating, painting and coating
- Inspection and nondestructive testing (visual, dye-penetrant, ultrasonic)
Common Injury Risks
Understanding the $2.758 Rate
The pure premium rate of $2.758 per $100 of payroll represents the loss cost portion — the expected claim cost per payroll dollar — before insurer loadings and adjustments. To calculate the base premium, multiply total class payroll by 0.02758; insurers then add expense loads, experience modification, policy-level credits or debits, and any schedule or deductible adjustments to determine your final premium. Payroll classification accuracy, your EMR, claim history and safety record materially affect the premium you actually pay.
Cal/OSHA Compliance Requirements
Valve manufacturing involves multiple Cal/OSHA General Industry standards: machinery guarding and lockout/tagout for control of hazardous energy, welding/cutting/brazing rules including ventilation and respiratory protection, Hazard Communication for solvents, coatings and plating baths, noise and hearing conservation, and confined space procedures when entering large pressure housings. Employers must maintain equipment guards, written lockout programs, SDS access, respirator and hearing conservation programs where exposures require them, and training specific to pressure testing and NDT operations.
How Key HR Helps Employers Under Class Code 3634
A PEO like Key HR can help reduce costs by auditing classifications to ensure accurate payroll allocation, administering claims and return-to-work programs to limit lost-time, and delivering safety programs and training tailored to valve shops (lockout/tagout, pressure-test protocols, welding ventilation). We also help manage California-specific compliance, coordinate medical care through preferred networks, and offer pooled experience and program-level solutions that can lower your effective workers' comp expense.
Get a QuoteFrequently Asked Questions
Does valve repair/overhaul belong under Class Code 3634?
Yes — independent repair and overhaul shops that disassemble, machine, weld, reassemble and pressure-test valves are typically classified under 3634. If a business only sells or installs valves without hands-on fabrication or testing, a different code may apply.
What practical steps lower workers' comp costs for valve manufacturers?
Focus on machine guarding, written lockout/tagout, trained welding ventilation and respirator programs, safe pressure-test procedures, ergonomics for lifting, and a formal return-to-work plan. Accurate payroll coding and timely claims management also reduce experience modifiers and premium.
Are hydrostatic and pneumatic pressure tests especially dangerous and regulated?
Yes. Pressure testing can produce ruptures or projectile hazards; employers should use engineered test stands, shields, pressure-relief devices, qualified operators, written procedures and PPE. Cal/OSHA requirements for equipment guarding, safe work procedures and confined-space entry (when applicable) must be followed.
Quick Facts
- Class Code
- 3634
- Classification
- Valve Mfg
- Pure Premium Rate
- $2.758 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
Manage Workers' Comp Through a PEO
Key HR provides pay-as-you-go workers' comp for California employers — no large deposits, no audits, better rates.
Get a Quoteor call (800) 922-4133Ready to Simplify Workers' Comp for Class Code 3634?
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