full lug butterfly valve

Butterfly Valve Full Lug Type D373H Series | Bi-Directional Isolation for Industrial Pipelines

The butterfly valve full lug type D373H from Shaanxi Qihe Xicheng Electromechanical Equipment Co., Ltd. covers diameters from DN50 to DN2000 and pressure ratings of PN10, PN16, PN25, and PN40. Designed and manufactured to GB/T12238-1989 with GB/T9113-2000 flange connections, it suits demanding industrial pipeline systems. The company holds ISO9001, CCC, CE, UL, GOST, CRCC, and CQC certifications, and each valve is pressure-tested per JB/T9092-1999 before shipment.

What Is a Full Lug Type Butterfly Valve?

A product features threaded inserts cast into the valve body and positioned around the outer flange. These lugs allow the valve to be bolted directly to a single pipe flange using individual bolts — no companion flange is needed on the opposite side.

This construction supports dead-end service. When a downstream pipe section must be removed for maintenance, the lug body retains pressure on the upstream side without requiring a full line shutdown. That capability matters in systems where modular maintenance or phased commissioning is part of the design.

By contrast, a wafer butterfly valve relies on bolts passing through both flanges simultaneously. Remove one flange and the wafer valve loses its seating load — making it unsuitable for end-of-line isolation.

D373H Technical Specifications

Design and Construction

The D373H lug-type body distributes bolt load evenly across each lug, reducing the risk of body distortion under pressure cycling. This is particularly relevant in large-bore installations where uneven loading can affect seat integrity over time.

The pressure range — PN10 through PN40 — means the same product family covers low-pressure water distribution and medium-to-high-pressure process lines. A diameter ceiling of DN2000 makes it applicable to trunk mains and large-scale infrastructure projects where comparable alternatives at that size are limited.

Flange seating faces are finish-machined to GB/T9113-2000 tolerances. Valve discs and stems are machined separately, then assembled with alignment checks before seat fitting. Each unit undergoes shell pressure testing and seat leakage testing per JB/T9092-1999 before leaving the production line.

Common Installation Scenarios

Industry Applications

The D373H is used in pipeline systems where reliable shut-off and dead-end capability are both required.

· Water Treatment & Distribution — DN200 to DN2000 for trunk mains and treatment plant pipelines

· HVAC Systems — PN10/PN16 rated units for chilled water and heating circuits

· Chemical Processing — PN25/PN40 for medium-to-high-pressure process lines

· Power Generation — Large-bore cooling water systems

· Fire Protection Systems — End-of-line isolation with lug body holding capability

· Industrial Utilities — Compressed air and process fluid control

Customization Options

Standard D373H butterfly valve full lug type configurations cover a wide range of applications. Where project requirements differ, the following adjustments are supported:

· Bore diameter selection within DN50–DN2000

· Pressure class selection across PN10, PN16, PN25, and PN40

· Body, disc, and seat material selection for fluid compatibility

· Flange drilling patterns per customer-specified standards

· Shipping arrangements including sea freight, air freight, road transport, and multimodal options

To get a recommendation based on your pipeline specifications, Contact Us at XCMOTORs@163.com with your required diameter, pressure rating, and quantity.

Quality System and Certifications

All D373H valves are manufactured under ISO9001 quality system certification. Additional certifications held by Shaanxi Qihe Xicheng include CCC, CE, CQC, CRCC (Ministry of Railways), UL, and GOST.

Valve inspection follows JB/T9092-1999, covering shell pressure tests, seat leakage tests, and operational torque verification. These tests are completed on each unit before shipment.

The factory operates on an SAP management system, providing order tracking through each production stage.

Company Background

Shaanxi Qihe Xicheng Electromechanical Equipment Co., Ltd. has over 20 years of experience in industrial equipment supply. The company maintains long-term supply relationships with more than 30 equipment manufacturers, including ABB, Siemens, Wolong, and XEMC. Technical support is available pre-sale, during order fulfilment, and after delivery, including weekends.

FAQ

Q: What distinguishes a lug butterfly valve from a wafer butterfly valve?

A: A lug-type valve has threaded inserts that allow bolting to a single flange, enabling dead-end service. A wafer valve requires bolts to pass through both flanges and cannot maintain seating load if one flange is removed.

Q: What sizes are available in the D373H series?

A: The D373H covers DN50 through DN2000, applicable to small branch lines through large-diameter trunk pipelines.

Q: Which pressure ratings does the D373H support?

A: PN10, PN16, PN25, and PN40 — covering standard industrial, infrastructure, and medium-pressure process applications.

Q: What standards govern design and testing?

A: Design and manufacture: GB/T12238-1989. Structural length: GB/T12221-2005. Flanges: GB/T9113-2000. Inspection and testing: JB/T9092-1999.

Q: Can you adjust the flange drilling pattern to match our existing pipeline?

A: Yes. Custom flange drilling patterns are supported to match existing pipeline infrastructure.

Q: How do I request a quote for a product order?

A: Email xcmotors@163.com with your required diameter, pressure rating, quantity, and any special material or delivery requirements. We respond within one business day.

Contact Us

Send your butterfly valve full lug type project specifications to xcmotors@163.com. Our team responds within one business day, including weekends. We support enquiries for the full D373H range.

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