Butterfly Valves

Butterfly valves across 50,113 listed configurations — wafer, lug and flanged bodies, DN40–DN1200, PN6 to ASME 300 — for water, HVAC, process and hydrocarbon service. Compare options and submit an RFQ.

Sourcing at a Glance

HS Code(s)

8481.80 (6-digit; 8-digit ITC-HS pending CHA confirmation)

MOQ Range

Quoted per order

Sample Lead Time

Quoted per order

Production Lead Time

Quoted per order

FOB Basis

Quoted per order

Standards / Certifications

API 609, EN 593, ASME B16.34, AWWA C504, EN ISO 16136

Specifying Butterfly Valves: Body Style, Offset, Seat and Class

How to choose between the three design families. Concentric resilient-seated valves place the stem on the disc centreline with an elastomer liner forming the seal; they are the lowest-cost family and the default for water, HVAC and utility isolation at moderate pressure and temperature. High-performance double-offset valves displace the stem from both the seat plane and the bore centreline, so the disc cams away from the seat on opening — reducing wear and enabling higher ratings, up to ASME 300 in the Himalay catalogue. AWWA rubber-seated valves are purpose-designed for waterworks service to AWWA C504. A note on triple-offset designs: these serve metal-seated high-temperature and hydrocarbon duty and are specified under API 609 Category B; they are not currently part of the Himalay butterfly catalogue.

The specification checklist. Seven points decide most butterfly valve selections, and all seven are hard requirements in a complete enquiry: service medium; nominal size (DN or NPS); pressure class; face-to-face standard; end connection; body material grade; and seat material with its temperature window. Add operation type — lever, gear, or actuation — and, for automated valves, the fail-safe mode and required actuator torque.

Size and class coverage. The catalogue spans DN40 to DN1200 across 50,113 configurations. Pressure classes by family: concentric resilient-seated valves run PN6–PN25 and ASME 150; high-performance double-offset valves run PN25–PN40 and ASME 150–300; AWWA rubber-seated valves carry Class 150B and 250B. In AWWA designations the class number is the maximum steady-state working pressure in psig, and the "B" suffix denotes a 16 ft/s maximum line velocity rating.

Materials against service. Ductile iron (GGG40/A536) with an EPDM liner is the workhorse for water and HVAC. Carbon steel (A216 WCB) and CF8M stainless cover general process duty; duplex 2205 serves seawater and high-chloride streams; aluminium bronze (B148 C95800) is the marine-service alternative; 6Mo/254 SMO addresses severe chloride and brine service. PVC-U and CPVC bodies to EN ISO 16136 suit corrosive water-treatment chemicals; catalogue thermoplastic valves are PN10-rated, with material temperature limits of roughly 55 °C for PVC-U and 95 °C for CPVC per published maker data — well inside the standard's overall −40 °C to +120 °C thermoplastics scope. On seats: EPDM for water, NBR for oils, FKM for hydrocarbons at temperature, PTFE for chemical breadth (working limit roughly 200 °C), metal seats beyond that. For low-temperature duty, −29 °C is the conventional Charpy impact threshold below which low-temperature grades (A352) are specified.

Standards map. API 609 governs double-flanged, lug- and wafer-type butterfly valves in two categories: Category A concentric valves rated by manufacturer's cold working pressure, NPS 2–60 with Class 125/150 bolting patterns; Category B offset-seat, pressure-temperature-rated valves in Classes 150–600. EN 593 is the European general-purpose metallic butterfly valve standard, covering wafer, lug, flanged and butt-weld ends from DN20 to DN4000 and ratings PN2.5 through Class 900. AWWA C504 covers rubber-seated waterworks valves 3"–72" for fresh water between 0.6 °C and 52 °C. EN ISO 16136 covers thermoplastic butterfly valves DN15–DN600 with a 25-year design life. Design verification on ASME-pattern valves references ASME B16.34 pressure-temperature ratings.

Import conformity by destination. EU: PED 2014/68/EU categorisation (Article 4.3/SEP through Category IV) with the matching conformity module and CE marking; EN 10204 3.1 material certificates are the standard procurement baseline. Saudi Arabia: SABER platform conformity is mandatory for imports. UAE: ECAS conformity applies. Sour hydrocarbon service additionally invokes NACE MR0175 material limits on all wetted parts. Fire-safe certification to API 607 or API 6FA applies where hydrocarbon isolation demands it — state it explicitly; it changes seat and body verification.

From spec to RFQ. A complete butterfly-valve enquiry states: medium, DN/NPS, class, face-to-face, ends, body grade, seat, operation, destination market and any fire-safe, NACE, potable or hygiene requirement. With those ten points, quotations are comparable line-for-line across makers — and anything not stated becomes an assumption a supplier must guess at. Share the line spec or datasheet with your RFQ and the configuration is matched against the catalogue directly.

How Butterfly Valves Work

Mechanism: a disc on a shaft that stays in the flow path at every position. A butterfly valve's "valve configuration consists of a stem and disc that rotate 90° from open to close." Because the disc never leaves the bore, its angle at any point between the two stops sets the open area directly: "when the disc aligns itself parallel with the flow, it allows maximum fluid passage. Conversely, when it is set perpendicularly, the fluid can be fully restricted." The catalogue's high-performance double-offset family displaces the shaft from both the disc and seat centrelines, which produces "camming action, moving the disc away from the seat rather than across it, reducing rubbing between the disc and seat" on opening. That reduced-rubbing geometry — rather than a thicker liner — is what lets an offset design carry the higher pressure classes and longer seat life a concentric resilient-seated disc cannot reach.

Industries served: wherever a large bore needs light, fast isolation rather than a heavy gate. Resilient-seated butterfly valves see the widest spread of duty: "isolation and control applications including HVAC, chemical and petrochemical, food and beverage, power generation, water and wastewater, oil and gas, mining and dry bulk handling." A second source narrows this to everyday installed base: butterfly valves "are commonly used in HVAC systems, water treatment, wastewater processing, chemical processing, food and beverage lines, and other industrial piping applications where dependable flow regulation is required." The same source notes that municipal water, wastewater and major process lines "often utilise double-flanged valves due to their stability" over the lighter wafer or lug styles — a distinction the catalogue's own end-connection range reflects directly.

Standards landscape: a metallic-valve code, a European general-purpose code, a waterworks code and a thermoplastics code — not one universal spec. API 609 governs double-flanged, lug- and wafer-type butterfly valves in two categories — Category A concentric valves rated by manufacturer's cold working pressure, and Category B offset-seat, pressure-temperature-rated valves — both listed on this catalogue. EN 593 is the equivalent general-purpose European standard for metallic butterfly valves, covering wafer, lug, flanged and butt-weld ends from DN20 to DN4000 across PN2.5 through Class 900. The catalogue's AWWA rubber-seated family instead follows AWWA C504, which covers rubber-seated valves 3"–72" for fresh water up to 250 psig working pressure. Thermoplastic-bodied valves follow EN ISO 16136, covering DN15–DN600 with a stated 25-year design life. Sources: [Valve Magazine — An Overview of Butterfly Valves](https://www.valvemagazine.com/articles/an-overview-of-butterfly-valves); [IQS Directory — Types, Materials, Functions and Benefits of Butterfly Valves](https://www.iqsdirectory.com/articles/butterfly-valve.html) ---

Frequently Asked Questions

Wafer, lug or double-flanged — which body style should I specify?

Wafer bodies clamp between pipe flanges and are the lightest and lowest-cost choice for general in-line isolation; lug bodies thread the flange bolts into the valve so one side of the line can be unbolted with the valve in place; double-flanged bodies carry their own integral flanges and are specified for larger sizes and buried or high-load installations. Himalay lists all of wafer, lug, flanged, double-flange and mechanical-joint ends across DN40–DN1200. Face-to-face interchangeability follows ASME B16.10 and EN 558 patterns — state your face-to-face standard in the RFQ for retrofit lines.

Can a wafer butterfly valve be used for end-of-line service?

No — a wafer body has no independent bolting and must be compressed between two live flanges, so it cannot terminate a line. For end-of-line or dead-end duty, specify a lug body, which retains the downstream bolting independently. Confirm the required shutoff differential in the enquiry, since dead-end ratings are configuration-specific.

When do I need a double-offset (high-performance) butterfly valve instead of a concentric one?

Specify double-offset when pressure, temperature or cycling exceed what an elastomer-lined concentric valve tolerates — the offset geometry lifts the seat clear of the seal on opening, extending seat life at higher ratings. Concentric resilient-seated valves remain the economic choice for water, HVAC and utility duty at moderate conditions. Himalay lists both families: concentric up to PN25 and ASME 150, double-offset up to PN40 and ASME 300.

Which seat material should I choose for my medium and temperature?

Match the seat to the medium first, then check its temperature ceiling: EPDM for water and non-oily service, NBR for oils, FKM for higher-temperature or aggressive hydrocarbon duty, PTFE (RTFE) for broad chemical resistance, and metal seats where soft materials cannot survive. As a working limit, PTFE seats are used to roughly 200 °C. Service medium and operating temperature are hard specification points — state both in the RFQ.

Are potable-water approved butterfly valves available?

Yes — waterworks butterfly valves are listed to AWWA C504, which covers rubber-seated valves 3"–72" for fresh water at up to 250 psig working pressure. For potable-contact approvals such as WRAS-listed elastomers, state the requirement in the RFQ so the seat specification is confirmed against it.

What conformity documentation applies for EU, Saudi and UAE imports?

EU-bound pressure equipment is categorised under PED 2014/68/EU with CE marking per the applicable module; Saudi imports require SABER conformity; UAE imports require ECAS. Material traceability to EN 10204 3.1 is the common EU procurement baseline. State the destination market in the enquiry so certification scope is quoted correctly.

Do you list hygienic or sanitary butterfly valves?

Sanitary butterfly valves are not part of the current listed catalogue — hygienic duty is handled as a specified requirement quoted per enquiry rather than a stock configuration. State the sanitary specification needed (e.g. 3-A, surface finish, FDA-grade elastomers) and the CIP/SIP temperature cycle in the RFQ, and the requirement is matched at quotation stage.