Protection and dependability of sealing are critical in several oil and gasoline, chemical, water, slurry and multi-product or service apps.API’s DBB definition won't achieve the same amount of isolation as OSHA’s definition. API will allow DBB valves being one particular one valve with two unidirectional seats, when the OSHA regular http://gunnermuwyb.xzblogs.com/17525856/everything-about-double-block-and-bleed-valve