Flexible (semi-rigid) appliance fuel connectors are typically used with cooking ranges and clothes dryers where the gas connection is located behind the appliance. Some degree of flexibility is needed to facilitate the hook-up of the appliance. Flexible connectors are usually made of stainless steel. They should be labeled with tags of metal rings placed over the tubing.

https://youtu.be/dse-WcdjA2s

Piping should be supported to ensure alignment and to prevent sagging. Piping in the ground should be laid on a proper bed. Piping above ground should be supported with hooks, straps, bands, brackets and/or hangers suitable for the size of the piping, of adequate strength and quality, and located at intervals so as to prevent sagging, damage and vibration. Other piping should not support piping. Piping should not put strain upon connected equipment or appliances.

Individual, branch and circuit vents are permitted to terminate with a connection to an individual or branch-type air-admittance valve. Stack vents and vent stacks should be permitted to terminate to stack-type air-admittance valves. Access should be provided to all air-admittance valves. The air-admittance valve should be rated according to the size of the vent to which it is connected. www.nachi.org

Where the drainage system cannot drain by gravity to the sewer, an automatic pump or ejector can be used to discharge the soil and waste. The cover for the pump should be tightly sealed (gas-tight). Sumps, other than pneumatic ejectors, should be vented with a minimum 1-1/4-inch diameter vent pipe. Pumps use mechanical methods to discharge, and pneumatic ejectors use air pressure. Grinder pumps and ejectors pulverize solids to a near-liquid state and pump the slurry to the drainage system.

All cleanouts should be accessible or reachable without having to remove a permanent portion of the structure. Cleanouts are designed to make the interior of a drainage system accessible for clearing stoppages without inconvenience, dismantling wall or ceiling finishes, or disturbing the sanitary drainage system.Cleanout plugs are very common. They are usually located at changes in direction in a drain line and at the bottom of stacks. Cleanouts should be installed to open and allow cleaning in the direction of the flow of the drainage pipe, or at right angles thereto. They must be water-tight and gas-tight. A cleanout plug can be made of brass or plastic. A cleanout plug should have a raised square or a counter-sunk square head where a trip hazard may exist. The square shape minimizes the possibility of stripping the plug during removal.

Modern plumbing, including proper sanitary drainage, is one of the reasons that diseases such as typhoid fever, cholera and dysentery have been eliminated. Modern plumbing has improved human health and longevity.

Globe valves tend to be restrictive, but can be used to control water flow.

In the connection of a water distribution system to water-heating appliances, there is the potential for the migration of heated water into the water distribution piping. In a typical water distribution system, the water will expand into the public water service. If the expansion of water is not accommodated in the system, dangerously high pressures can develop that can cause damage to piping, components and the water heater.

Water Pressure Defects

In order to get the most meaningful results in relation to inspecting the water pressure, it is good practice to inspect the plumbing fixtures at the highest point in the house. And then move downwards to the lowest level of the building while running water at each fixture for a minute or two. Do not let water run at any fixture without close observation. Do not let water run unattended at any fixture.