Top entry butterfly valves are different with side entry butterfly valves, top entry butterfly valves are designed able to disassemble valve and take trim out without remove valve from pipelines. Usually these valve are metal seated triple eccentric with weld connection.
The cost of top entry butterfly valves are higher than side entry butterfly valves much more. but it deserves it sometimes. These valves are designed with carbon steel/alloy/stainless steel material body and disc. Pressure scope: PN2.5 ~PN40. Design standard: EN593 or API609.
Top entry three eccentric butterfly valves with weld ends PN25 DN600 Multi-layers seal ring: SS+graphite.
Side entry triple offset butterfly valve with weld ends