Analysis of the difference between similar pneumatic valve figure number

jh as the difference between the pneumatic valve and pneumatic valve jf deadline
jh and jf distinction is the difference between h and f, also is the sealing surface of different material, h is Cr stainless steel sealing surface material of jh, jf is fluorine plastic f said sealing surface of materials.
the difference between the hx and hx
the difference between the hx and hx is the different structure forms, the said structure hx is swing pneumatic disc double disc structure and form of the second representation structure of hx is butterfly check type.
butterfly pneumatic valve type dx is different from dx
the difference between the butterfly pneumatic valve type dx and dx is the difference between the drive mode, drive mode is dx said in turbine, and no driver code in dx, the dx drive way is to handle the handwheel.
butterfly pneumatic valve dx with dx distinction
dx with dx is the difference between a connection form and structure in the form of different, dx connection form is, to the clamp structure is sealed type center vertical plate, the connection forms of dx is flange connection, the structural form is triple eccentric sealing type.
what is the difference between dx and dh
the distinction between dx and dh is the sealing surface of different material, the dx x said sealing material is rubber, dh h sealing material is Cr in stainless steel.
the difference between the butterfly pneumatic valve type dx and dx
the difference between the dx and dx is the different structure forms, the second said drive form dx is sealed type triple eccentric, said drive form in the dx is sealed type center vertical plate.
　　zh- With useful - Is there a difference?
　　zh- With useful - The difference is that different nominal pressure, useful - Is said in the nominal pressure. MPa，zh- Is said in the nominal pressure. MPa。

hh and hw difference between hh and hw difference is the different seal material, hh h sealing material is Cr in stainless steel, the hw w said sealing material is a direct processing of pneumatic valve body.