SPDCV15 Speed Plumb 15mm Double Check Valve (68 ratings) £11.08 Quantity: at £11.08 each Add To Basket SPDCV15 - 15 mm Double Check Valve. Speed Plumb push fit plumbing system range is available in 12 & 15mm sizes. The fittings contain stainless retention teeth, making the fittings suitable to connect securely to hard surface plastic and metal fittings and piping. Our push fit plumbing fittings and accessories are produced to high standards for food grade applications complying with WRAS and US FDA standards. The system has a MAXIMUM working temperature of 65 degrees Celsius.