Domestic water plumbing systems are one of the highest liability systems in a home or building. Water damage from a failed plumbing can result in significant claims and in a domestic plumbing system, not only are you routing water throughout a building – those water pipes are held under constant pressure.
Water pressure can wreak havoc in a plumbing system in two ways:
While burst pressure is the most frequently considered pressure concern, degradation related pressure limits are increasingly becoming a factor in building using PEX plumbing systems.
The plumbing codes require that all domestic water plumbing systems be pressure rated at 100psi at 180°F, this means that the system must be capable of handling at least 100psi of pressure at 180°F without ballooning or bursting. The codes, however, do not specify a minimum pressure rating at lower temperatures.
At room temperature, FlowGuard Gold® CPVC is pressure rated to 400psi and at all normal operating temperatures (up to 140°F) FlowGuard Gold CPVC is pressure rated above 200psi. That means you will never have to worry about an over-pressure situation in a FlowGuard Gold potable water system.
Unfortunately, PEX plumbing systems are pressure rated at as much as 60% lower than a FlowGuard Gold plumbing system. With a maximum pressure rating of 160psi, it is entirely possible for system pressures in a multifamily or commercial building to exceed the rated pressure for a PEX system.
FlowGuard Gold Plumbing Systems can handle the pressure regardless of local water conditions, however with a PEX plumbing system the presence of chlorine can significantly reduce the pressure capacity of the pipe.
Per the chlorine resistance test standard ASTM F2023 and Plastics Pipe Institute Technical Note-53, in chlorinated water PEX is not intended for use at pressures over 80psi. This limitation is not because the pipe will burst above 80psi, but because the pipe becomes significantly more vulnerable to the influence of chlorine degradation at higher pressures.
When a PEX plumbing system handling chlorinated water operates at pressures above 80psi, there a significant increase in the risk of chlorine-induced degradation, pin-hole PEX leaks and failures.
Chlorine degradation on PEX piping taken from a home in Washington
Water pressure in a building is typically under 80psi, but the pressure limitation on PEX can easily be exceeded under many circumstances.
Water pressure can have a significant impact on plumbing system performance. Whether you’re looking for an extra safety factor in a larger building or in a residential building where pressures may exceed 80psi – a FlowGuard Gold CPVC plumbing system can handle the pressures that PEX systems simply cannot.
While mechanical systems like expansion tanks and PRVs can be added to reduce the risk, mechanical pressure regulating systems are prone to failure and should not be relied on to prevent a piping system from exceeding its pressure limitations.
With a pressure rating of 400psi at room temperature and at least 200psi up to 140°F you can trust FlowGuard Gold CPVC to provide peace of mind that your plumbing pipes can stand up to the pressure found in your projects. If you’re still using a PEX plumbing system, it's time to make the switch. To speak to a representative about how FlowGuard Gold can help you build better homes, contact us now.