Brass or bronze fittings are common in copper piping and plumbing systems. The piping and valves are generally of stainless steel. These joining techniques are discussed in more detail in the piping and plumbing fittings article. They are usually constructed from heavy steel piping mounted on a steel frame. An automatic water supply provides water under pressure to the system piping. The interior plush velour upholstery was camel with dark brown piping. There is no piping around the sleeves. A Brayton cycle heat engine can operate at lower pressure with wider diameter piping. As with other Cadillac models, special order contrasting upholstery piping and exterior colors were available. The primary home uniform is white with navy piping around each sleeve. Leaks from tanks and piping are an environmental concern. The shirt was forest green with orange piping around the epaulets and shirt pockets. Steam is used in piping for utility lines. All had "silk grey" leather with black accent piping and silk grey velour carpeting. Maintain minimum scouring velocities in the piping and distribution network to ensure turbulent flow.