BUTTERFLY VALVE
Butterfly Valve Design Features
Butterfly Valve are used to open and close (seal type) or adjust the medium flow in pipes in the fields of foocstuff, drinks, chemical, industrial
water treatment, high-rise constructions, water supple and drainage etc.. They are mainly structured as following.
1. Simple structure, small sizes, light weight and low installation dimensions. According to the types of body connection, they are basically
classified to wafer type (including lug wafer type), flanged and welded.
Flanged Connection
Butt-welded Connection
Wafer Connection
Lug Wafer Connection
2. Sealing materials may be soft hard, placed on body or disc, to meet different working conditions, and to effect good seal and long fit.
(1) Soft sealing structure (see fig. right), is applicable for single and double eccentric butterfly valves, pressure rating <CLASS 600. Centred
sealing structure is applicable for pressure rating <CLASS 250. Sealing ring (PTFE) is placed on the valve body to feature the following.
a. To effected dependable sea with no need of accessorial sealing ring or metal bracing ring.
b. Bidirectional leakproof seal.
c. Little maintenance and long service lift.
(2) Multilayer Hard Seal Structure (See fig. right)
Multilayer hard seal structure is applicable for single, double and triple eccentric butterfly valves, pressure rating<CLASS 600. And, triple
eccentric butterfly valve can maintain two-way leak-tightness. Multilayer sealing ring is composite of stainless steel and nonmetal material.
The nonmetal material can be flex-ible graphite, PTFE or non asbestos material etc. according to he actual working conditions.
Soft Sealing Structure (Fig.a)
Multilayer Hard Seal Structure (Fig.b)
3. Elastic ring hard seal structure (see fig. right) is of the structure of J-type metal sealing ring. It is applicable for single and double eccentric
butterfly valves, pressure rating <CLASS 300, Prov-ided with fireproof structure to adapt to conditions with great temperature changes,
it is featured by outstanding seal. Long service life and easy workmanship.
3. Fireproof butterfly valves (see fig. Right) can stop the expansion of fire, Once the sealing seat of butterfly valves is on fire, the stainless
Steel sealing ring will act to make butterfly valve immediately sealed.
4. When butterfly valve is fully opened, flow resistance is low. When partially opened, it may carry our sensitive flow control.
5. Low driving moment, easy and quick operation.
Elastic Ring Hard Seal Structure (Fig.c)
Soft Seal Fireproof Structure (Fig.d)