Short Neck Lug Type Model 20: A Butterfly Valve Type Lug Supplier Selection Guide

1. Start with your working requirements

Before you compare models, write down:

• Nominal size of the line (inch or mm).
• Flange standard and drilling on the mating pipework (for example ANSI 125/150, PN10, PN16 or JIS 10K).
• Process medium and temperature range, including any chemical or abrasive content.
• Operation method: handle, manual gear operator, or electric or pneumatic actuator.
• Material preferences for the body, disc, stem and seat.

The Model 20 product page answers some of these points in detail and leaves others for you to confirm with the supplier.

2. What the Model 20 documentation covers

Body design

The product page says the one-piece bodies are ribbed to assure high strength and minimum weight.

Published materials list

The Model 20 body options are cast iron and ductile iron only.

Size range and selected dimensions (mm)

The Model 20 dimension table covers 2" to 12" (50–300 mm). Selected columns are below. The excerpt labels the columns with letters only, so read them against the supplier's drawing before you use them for layout.

The table also lists H, J and K values. These are 101.6 / 82.6 / 11.1 mm for 50–150 mm sizes and 152.4 / 127 / 14.3 mm for 200–300 mm sizes. If you plan to fit an operator, check these columns against the operator's mounting requirements.

3. Integration fit: flanges and operation

Flange drilling. The Model 20 has one set of E and M values per size. They match the ANSI 125/150 entries in the dimension table for the LUG TYPE BUTTERFLY VALVE. The LUG TYPE BUTTERFLY VALVE has those columns.

Operation. The Model 20 excerpt does not say which handles, gear operators or actuators are offered. In contrast, the LUG TYPE BUTTERFLY VALVE page lists handles, manual gear operators, and electric or pneumatic actuators for 2" to 12". The Long Neck Lug Type Model 30 page says its large top flange provides a secure mounting area for actuators. If you plan to actuate the valve, confirm the operator option for Model 20 in writing.

Temperature. The Model 20 page does not publish seat temperature ratings. The LUG TYPE BUTTERFLY VALVE page publishes ratings for its seats, for example EPDM −40 to 120 °C and PTFE −50 to 200 °C. It also warns that some flow media may further restrict these limits or significantly reduce seat life. Do not assume those ratings apply to Model 20 without confirmation. For any special medium or temperature, the supplier asks buyers to consult the company.

4. When another model may fit better

For comparison, the Model 30 B values (143 mm at 50 mm up to 310 mm at 300 mm) are higher than the Model 20 B values (100 mm up to 300 mm), which matches the short neck and long neck naming. Confirm the exact meaning of each dimension on the drawing.

The Model 20 recommendation does not apply if you need a body material other than cast or ductile iron, a size outside 2"–12", or documented compliance with a specific design standard. The Model 20 excerpt states no standard. The Series F170 page says it is designed to comply with MSS SP-67, BS5155 and API 609, but that statement belongs to Series F170 only.

5. Questions to settle with your butterfly valve type lug supplier

1. Confirm the flange standard and lug thread for every size on your order.
2. State the medium and operating temperature. The LUG TYPE page invites customers to mark the material and temperature used, and the company can then select the materials.
3. Specify the body, disc, stem and seat combination from the published list.
4. Confirm the operator type and top-connection dimensions.
5. Ask for a written quotation for pricing, lead time and any documentation you need. This article makes no claims about price, delivery or certification.

NINGJIN COUNTY HONGDA VALVE CO.,LTD. has published a full materials list and an inch/mm dimension table for the Model 20. You can check most of the integration questions above before you request a quotation, then use the supplier conversation to close the gaps.