BONETTI valves type BLB, are specifically designed for continuous blowdown.

The continuous blowdown valves are needle valves designed for operation in open position. Their function is mainly to control a continuous flow of steam and/or water under high Δp.

For that reason the design and materials must be such as to minimise the effects of a fluid stream in condition of flashing or made of water containing sometime abrasive particles.

The outlet of our valves is purposely Venturi tube-shaped. The bonnetless design enables easy dismantling, inspection and maintenance.

The stem is rising, non-rotating. A local stroke indicator shows the position of the disk.

In spite of the above mentioned features, it can happen that these valves - after some operating time - are not able to ensure a tight seal, since even a slow-acting erosion deteriorates the working surfaces of the disk and seat. What above does not affect its function; the only consequence is a slight rise in the outflow rate, the disk being in the same position, remediable by closing a little the valve. The orifice can be selected in accordance with the valve function and operative condition of the upstream pressure as well as of the flow rate.

The downstream pressure does not affect the flow rate, being usually lower than the critical pressure.

If a tight closure is needed after service, a BONETTI PBR valve for discontinuous service is the proper and best solution.

BLB applications:

BLB features:

• Bonnetless
• non-rotating stem (for continuous blowdown)
• minimizes the effects of a fluid cointaining abrasive particles
• operates with very high Δ pressure
• any actuator can be easy assembled