Abstract: An adapter for gas valves used for fireplaces and barbecues. The adapter bridges a distance between the gas valve and a finishing flange used to cover a hole in a floor or wall within which the gas valve T-junction is recessed. The adapter includes an inner length with female threading adapted to mate with the male threading on a valve control leg of the gas valve T-junction, and an outer length with male threading adapted to mate with the female threading on the finishing flange. The threading on the gas valve T-junction, adapter, and finishing flange is all parallel enabling maximum axial adjustment therebetween, and eliminating the need for expensive plumbing work to couple pipe elements with tapered threading therebetween. Multiple adapters may be coupled together to bridge longer distances. A gas key having an adjustable length couples with the adapter to provide fine length adjustment. The adapter may be a machined metal tube or a molded plastic element.