Frequently Asked Questions

Valve Questions, Answered.

Lead times, certifications, valve selection, codes, materials. Common questions from engineers, EPCs, and procurement teams — answered straight, no marketing fluff.

Working With Miller Valve

Who We Are & How We Work

The fundamentals — who we sell to, how fast we ship, what we stock, and how we handle international orders.

Who does Miller Valve sell to?
We sell to end-user plant operators, EPC firms, engineering contractors, OEMs, MRO procurement teams, and integrators. Our customers range from utility-scale power plants to specialty chemical operators and aerospace launch facilities. We don't sell to retail consumers — our products are industrial-grade severe-service valves spec'd into engineered applications.
What are typical lead times for valve orders?
For stock items in our most-requested sizes and configurations, we ship same-day. For engineered orders, specialty materials, or unusual configurations, lead times typically range from 2 to 12 weeks depending on the manufacturer. Cryogenic valves, high-pressure forged-body assemblies, and exotic alloy configurations tend to be on the longer end. For outage and turnaround urgency, we move engineered orders through the factory as fast as possible.
Engineering Support

Application Engineering & Documentation

How we help you spec, size, and document — beyond just shipping parts.

Can you help me select the right valve for my application?
Yes — that's the core of what we do. Our engineers help you size the right valve for your media, pressure, temperature, and code requirements. We don't just ship parts; we work with your team to spec the right product for the right application. Use our quote wizard to start, or call 205-871-7778 for a direct conversation.
Do you provide Cv calculations and control valve sizing?
Yes. We size control valves for liquid, gas, and steam service using the Cv method — factoring in choked flow, anti-cavitation requirements, noise attenuation, and rangeability. We work directly with our control valve partner Trimteck Optimux for engineered solutions on severe-service applications. Provide us your line size, flow rates, ΔP, and media — we'll size and recommend.
Can you provide certifications and material traceability?
Yes. We supply mill certificates, positive material identification (PMI), NDE reports (radiography, ultrasonic), hydrostatic test certificates, NACE MR0175 compliance documentation, oxygen-cleaning certs to ASTM G93 for LOX service, and full chain-of-custody traceability. Specific documentation packages depend on the product and your project requirements — tell us what your QA team needs.
Technical Selection

Choosing the Right Valve

When to use which valve type, what the codes mean, and how to think about materials and geometry.

When do I need a triple-offset butterfly valve?
Triple-offset butterfly valves (TOVs) are the right choice when you need bubble-tight metal-to-metal shutoff in a butterfly's compact footprint. Typical applications: steam isolation, hot hydrocarbon service, cryogenic service, high-cycle duty (over ~5,000 cycles/yr), fire-safe, and emergency shutdown. They're especially reliable in cryogenic service: where thermal contraction defeats soft seats, a TOV's torque-seated metal disc seats tighter as it closes, holding bubble-tight shutoff down to -320°F and below. Wherever a resilient-seated butterfly can't survive the temperature, pressure, or cycle count, a TOV can. Our partner Quadax specializes in TOVs.
What's the difference between metal-seated and soft-seated valves?
Soft-seated valves use elastomeric or polymer seats (PTFE, PEEK, etc.) that conform to the ball or disc surface for tight shutoff at moderate temperatures and pressures — they typically deliver Class VI bubble-tight performance. Metal-seated valves use hardened metal-to-metal sealing for high-temperature, high-pressure, or abrasive service where soft seats fail. Metal-seated trades a small amount of leakage allowance for the ability to survive in steam, hot hydrocarbons, fly ash slurries, and other severe service.
What does API 6D mean and when do I need it?
API 6D is the API specification for pipeline valves — ball valves, gate valves, and check valves used in transmission and gathering pipeline service. It includes design, testing, and qualification requirements that pipeline operators specify for isolation valves. If your spec calls for API 6D, the valve must be certified to it with documentation. It's standard for midstream pipeline projects and is often paired with API 607 fire-safe and ISO 15848 fugitive emissions requirements.
What's the difference between trunnion-mounted and floating ball valves?
Floating ball valves rely on the ball moving slightly downstream under pressure to seal against the seat — they're typically used for smaller sizes (up to 6–8 inches) and lower pressures (up to ANSI Class 600). Trunnion-mounted ball valves have the ball fixed on upper and lower trunnions, with spring-loaded seats that maintain shutoff regardless of pressure. Trunnion designs are required for larger sizes (8 inches and up) and higher pressures (Class 600+). For pipeline service, trunnion designs are nearly universal.
Quoting & Pricing

How to Get Pricing

Quote turnaround times, custom orders, and how to engage us.

How do I request a quote?
Three options: (1) Use our online quote wizard — it walks through your application, conditions, materials, and timeline step by step. (2) Email info@millervalves.com with your service conditions. (3) Call 205-871-7778 for a direct conversation with our engineering team. We respond to most quote requests quickly.
How long does it take to get a quote?
Same-day for stock items and standard configurations. 24–48 hours for engineered configurations or specialty alloys. For complex multi-line projects with hundreds of valves, we'll work with you to set realistic expectations and provide phased pricing as we work through the bill of materials.
Do you handle custom or engineered-to-order valves?
Yes. Many of our orders are engineered-to-order — specialty materials (Hastelloy, Inconel, titanium, duplex), unusual sizes, custom trim selections, fire-safe or fugitive-emissions packages, oxygen-clean preparation, and other configurations that aren't off-the-shelf. We work directly with our manufacturer partners' engineering teams to spec, quote, and deliver.

Don't See Your Question? Let's Talk.

Our engineers respond to most inquiries quickly. Skip the search — get a real answer from a real engineer.

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In loving memory of our founders and friends, Wayne and Lawton Miller