Plumbing is the system of pipes and fixtures that facilitates the distribution of water and the removal of waste. It is a vital part of modern buildings and is regulated by state authorities to ensure safety and efficiency.
Backflow testing is required for most multifamily residential and commercial properties. It is triggered by any significant change in water pressure, which could be caused by a water main break or heavy usage. Contact Plumbing Express, Inc. for professional expertise.
Water pressure is what drives the flow of water through your pipes and taps. It affects how fast your shower or washing machine runs, and it also plays a role in backflow testing. But do you know how water pressure is measured? Or how it differs from water flow? The difference is important, because it can help you understand the root cause of your plumbing issues.
Your water pressure is largely determined by the altitude of your building, as well as the size and texture of your pipes. It can also be influenced by the type of water tower your house is connected to. Pressure is also affected by friction and resistance, as well as water loss due to leaks, loose connections, and other factors.
A good rule of thumb is to keep your water pressure below 80 psi, as any higher and you can start to experience problems. These include low water pressure to all parts of your home, restricted valves and faucets, shortened pipe, tubing, and appliance life cycles, noise, leaks from taps, baths, garden hose taps, toilet cisterns, water hammer, clogged drains, and much more.
If you notice that your water pressure has suddenly dropped, you can try a few different things to solve the problem. First, you can check to see if the water meter valve is open. This is usually located near the front of your property and has a handle similar to that of a garden hose valve. If it is turned counterclockwise, you should turn it clockwise to fully open it.
Another possibility is that your pipes are clogged with sediment. This can reduce your water pressure significantly, so you should call in a plumber to clean them out with a hydro jetting solution. You should also be sure to replace any restrictive valves or aerators, as these can restrict the amount of water that is flowing through them.
If you live in an apartment or condo building with shared water lines, it is possible that your neighbors are causing your water pressure to drop. This can happen when multiple people are using the same water at the same time, especially if they all run their dishwashers or take long hot showers at the same time.
Check Valve
A check valve is a one-way valve that is designed to prevent backflow. These valves are a critical part of any backflow protection system as they can prevent treated water or chemicals from flowing backward into untreated water, waste materials, or even into other systems where backflow could cause contamination. Check valves are like the traffic cops of fluid systems, firmly stopping wrong-way flow before it can cause problems.
Unlike a pressure-operated ball valve that requires a specific amount of upstream pressure to open, a check valve is held closed by its own force. This force is created by a spring that helps to keep the valve’s internal components in contact with each other. When fluid pressure is applied to the valve, this force is overcome and the check valve opens. The amount of pressure required to overcome this force is called the cracking pressure. This value varies by valve design and size, so it is important to choose the right type of check valve for your needs.
There are several different types of check valves, with the most common using either a cone or a ball for the sealing element. When fluid pressure is applied in the direction of the arrow on the valve body, this pressure causes the clapper or ball to be forced off its seat and open. Once the valve is open, the clapper or ball stays in its new position and keeps the valve from closing.
Another way that a check valve can help prevent backflow is by restricting the amount of fluid that can move through the valve when it is not fully opened. This type of valve is called a one-way restriction valve. It is commonly used in applications that require a high degree of purity, such as pharmaceutical manufacturing or food processing.
The key to ensuring that a check valve works properly is correctly installing it in the correct orientation. The valve must be positioned so that the normal flow of fluid through it is in the direction indicated by an arrow stamped on the valve body. Orienting the valve incorrectly will prevent the media from passing through it and can result in cracking or deforming the valve.
Relief Valve
In the event that the pressure of system fluid exceeds the pressure limit of the backflow preventer, the relief valve is designed to open and discharge the overpressure volume of gas, vapor or liquid to the atmosphere. The relief valve is one of the most important safety mechanisms in a backflow prevention assembly and is commonly used on oil and gas production systems, compressor stations, gas transmission (pipeline) facilities, storage systems, and backflow testing laboratories.
The physical appearance of a relief valve is similar to that of a pressure governor except the relief valve disc lifts off its seat under system pressure, instead of being forced onto it like in a governor. The pressure on the seat exerts a force against the relief valve disc that is less than the preload force of the spring and opens the valve to allow flow through the valve outlet.
A set screw or nut is provided on the top of the valve to adjust the pressure setting point. Screwing the nut clockwise increases the amount of force needed to compress the relief valve spring revealing the disc and opening the valve. Screwing the nut counterclockwise decreases the pressure setting and tightens the spring causing the disc to close and seal the valve outlet.
During normal operation, the pressure on the disc will be equal to or less than the relief valve setting. The incoming system pressure acts on the area A and when this pressure exceeds the setting point, the pressure will act on the area B which is twice as large as the pressure on area A. The pressure acting on area B will cause the valve to open and discharge the overpressure volume of fluid to the atmosphere through the vent opening.
One of the most common errors made by backflow testers is opening the low bleed during a test when a relief valve discharges, thereby causing a false negative result. This occurs because the system pressure rises past the leaking second check into the area between the first and second checks. Since the second check is leaking, the pressure in this area is higher than in the first check and can cause a condition known as disc compression which will lead to the relief valve opening and allowing system pressure to enter the backflow preventer.
Inspection
Backflow testing involves evaluating and assessing the functionality of backflow prevention devices in your plumbing system. During this process, an expert plumber will inspect the backflow prevention device and plumbing system to determine if it’s functioning properly. Then, they will set up and connect specialized equipment to the backflow prevention device to measure flow rates and water pressures. These tests include a forward flow test and a simulated backflow test to ensure the prevention device is stopping water from flowing in the wrong direction.
While backflow is a risk in any building, it’s especially dangerous in apartment and condominium buildings. Because these types of properties have shared water supplies, backflow incidents can impact multiple households simultaneously. This makes backflow testing and maintenance essential for the safety of residents and the integrity of the water supply.
During the inspection, a plumber will examine the outside of the property to look for cracks or other damage that could lead to leaks and pest infiltration. They’ll also inspect the plumbing and electrical systems to make sure they’re working well. Additionally, they’ll check for the condition of the sewer line to see if it’s clogged or leaking.
