Improve maintenance safety with Spirax Sarco’s new single unit for safe double isolation

Steam and fluid systems can be upgraded quickly and easily to safer and more cost-effective maintenance procedures with the new space-saving Spirax SafeBloc™ Double Block and Bleed (DBB3) Valve. The design of new plant layouts is also simplified.

This innovative, patented design incorporates two isolation valves and a bleed port in a compact assembly, making it easy to install into the space left by an existing single isolation valve. No other commercially available product provides double block and bleed isolation in such an integrated, compact unit.

The Spirax SafeBloc has ANSI or EN standard face-to-face dimensions, enabling it to replace an installed standard single isolation valve, without pipework modifications. A retrofit can be undertaken quickly, eliminating the time-consuming and expensive pipe cutting, welding and pressure testing needed to engineer a conventional double block and bleed arrangement from separate isolation and bleed valves.

Significant plant space is saved, with the Spirax SafeBloc taking up only a third of the pipeline length compared with conventional fabricated arrangements. This enables double block and bleed to be installed in spaces where it may otherwise be impossible.

Spirax SafeBloc uses proven technology from the Spirax Sarco range of bellows sealed globe valves that offer zero gland leakage, while ensuring tight shutoff conforming to DIN 3230 BO1 and ISO 5208 Rate A specifications. The unit’s internal flow path offers the same minimal pressure drop as conventional arrangements.

Double block and bleed enables a section of plant to be safely isolated for maintenance without having to shut down the entire system. Double isolation is achieved by closing both isolation valves, with the bleed valve being left open to ensure that the downstream pipeline remains isolated during maintenance work. This is widely recognised throughout industry as being best practice for safe plant maintenance.

With a carbon steel body and stainless steel internals, Spirax SafeBloc is available from DN15 to DN100 and flanged to PN40 or ANSI 300. Spirax SafeBloc can be used on general steam plant as well as other fluid systems, such as hot water.

Spirax Sarco, Tel: 01242 521361

Published: 25th September 2009