Abstract: A method of assembling a tubular simulated cigarette, the method comprising providing an elongate hollow housing having an inhaling end and a refill end; inserting an outlet valve tube, a dip tube and a support from the refill end so that the support supports the proximal end of the dip tube in the housing; inserting a refill valve into the refill end and fixing it in place to form a composition reservoir with the dip tube placing the reservoir in fluid communication with an outlet orifice when the outlet valve tube is open; inserting a valve element into a recess in the side of the housing so that the valve element is positioned to selectively close the outlet valve tube; inserting a breath operated valve actuation mechanism laterally into the recess; and applying a cover to the recess.