Are there some types of empty field mining laws? What are the applicable conditions for each method?

The open field mining method can be divided into the following five categories: comprehensive mining method, room and pillar mining method, mining and mining method, stage mining method, and section mining method.
The applicable conditions of the room and pillar mining method are: (1) the ore body and the surrounding rock are stable; (2) the ore body inclination angle is not more than 30 degrees; that is, the horizontal and gently inclined ore body. (3) Ore bodies with low or low grade ore.
Conditions for use in mining and mining: the thin and extremely thin steep ore body segmentation of the ore and surrounding rock are applicable. Conditions: mediumly stable, inclined, medium thick and thick ore body.
Applicable conditions of the stage mining method: the steep and thick ore body with stable ore and surrounding rock.

Lug type butterfly valves have threaded inserts at both sides of the valve body. This allows them to be installed into a system using two sets of bolts and nuts. The valve is installed between two flanges using a separate set of bolts for each flange. This setup permits either side of the piping system to be disconnected without disturbing the other side.

A lug type Butterfly Valve used in dead end service generally has a reduced pressure rating. For example a lug type butterfly valve mounted between two flanges has a 150 psi pressure rating. The same valve mounted with one flange, in dead end service, has a 75 psi rating.

Lug Butterfly Valve

Lug Butterfly Valve, Resilient Seated Lug Butterfly Valve Supplier, Eccentric Lug Butterfly Valve Manufacturer, Centerline Butterfly Valve, Offset Butterfly Valve, Stainless Steel Butterfly Valve Manufacturer

Wenzhou Kolink Valve Co., Ltd. , https://www.kolinkvalves.com