Home › Forums › Coking › Operations › Cutting, Drilling, Unheading › Unheading › How fast is Deltavalve? This topic contains 1 reply, has 2 voices, and was last updated by antonio saura Cebrian 13 years, 9 months ago. Author Posts August 17, 2007 at 5:19 pm #3968 Anonymous does anyone know how long to take deltavalve or equivalent to open and close? thanks a lot ! Tim August 27, 2007 at 8:17 am #7314 antonio saura CebrianParticipant Valve open / closed stroke time between 2 to 3 minutes Best regards Author Posts You must be logged in to reply to this topic.