SANITARY DRAINAGE SYSTEM INSTALLATION REQUIREMENTS

Backwater Valves

Backwater Valves
1. Install a backwater valve to protect fixtures whose flood rim level is below the closest upstream public sewer manhole cover.
2. Install the backwater valve in the building drain or in any branch drain that serves the fixtures requiring protection.
3. Do not discharge fixtures that have flood rim levels above the closest upstream manhole cover
through the backwater valve.
4. Provide access to the backwater valve through a water tight cover.
5. Use only approved backwater valves constructed with parts that will not corrode and will provide a positive mechanical seal.
6. Install a backwater valve that has at least (≥) the same capacity as the pipes served.

 

Drain and Sewer Fittings Installation

Drain and Sewer Pipe Fittings for Changing Direction of Flow
1. Use the fittings in the following table to change the direction of flow in drainage and sewer pipes.

Drain and Sewer Pipe Fittings Changing from Horizontal to Vertical Using Multiple Connection Fittings
1. You may use a multiple connection fitting (such as a double sanitary tee, a double fixture tee, or a double tee-wye) to connect two or more fixtures or to connect two or more branch drains coming from two different directions if the connection is: (a) from fixtures that are on the same level, and (b) from the same size pipe, and (c) from similar fixture types or fixture groups.
2. Do not use a double sanitary tee to receive discharge from back-to-back toilets and from fixtures or appliances with pumping action (such as washing machines and dishwashers). Use a double fixture tee or a double tee-wye instead. You may use a double sanitary tee to connect two toilets if the distance between the center of the closet    flange and the inlet of the sanitary tee is at least (≥) 18 inches. Read the full Topic

Drain and Sewer Pipe Cleanouts

Cleanout Locations and Spacing
1. Install a clean-out in every horizontal drain pipe so that the distance between clean-outs is not more than (≤) 100 feet, measured along the length of the pipe. Install at least (≥) one clean-out for every horizontal drain pipe regardless of length of the drain pipe. This provision applies to the building drain, building sewer, and horizontal branch drains.
2. Install a clean-out near the junction of the building drain and the building sewer. You may install this clean-out inside or outside the building. Make this clean out accessible at the lowest floor level inside or at grade level outside. You may install this clean-out in at least (≥) a 3 inch diameter soil stack if the clean-out fitting is not more than (≤) 10 feet from the building drain connection to the building sewer. Measure the 10 feet along the developed length of the pipe from the clean-out
fitting to the building drain and sewer junction.
3. Install a clean-out near the base of every vertical waste or soil stack. You may install this clean-out in the vertical stack or in the horizontal drain pipe.
4. Install a clean-out at every change of pipe direction of more than (>) 45 degrees when the direction change uses one fitting. You do not need to install a clean-out if the change in pipe direction uses two or more fittings. When multiple direction changes occur in one pipe run, only one clean-out is required spaced not more than (≤) 40 feet apart. This provision applies to the building drain, building sewer, and horizontal branch drains. Example: A direction change using one 1/4 bend fitting requires a clean-out, but a change in direction using two 1/8 bend fittings does not require a clean-out.

Read the full Topic

Drain and Sewer Pipe Fittings

Drain and Sewer Pipe Fittings Discussion

Drain and sewer pipe fittings are used for changing the direction of flow and are different from fittings used in water service and distribution pipes. Drain and sewer pipe fittings must provide a smooth change in direction and must maintain adequate flow velocity to reduce blockage in the
system. Concern about direction change and velocity is because water in drains and sewers flows by gravity and may contain solids. You may not use elbows and other fittings intended for water under pressure with drainage and sewer pipes. You may not use fittings intended only for vent pipes with pipes that carry liquids. Drain and sewer pipe fittings come in many different types and configurations. Some fittings have openings that are all the same size and some fittings have reduced sizes for some openings. Some fittings are double fittings with openings on both sides of the fitting. Some fittings combine different types of fittings into one fitting, such as the combination wye and 1/8 bend. Some fittings have all female openings (called hubs) and some fittings have a male and a female opening (called a street fitting). Fittings produced for some types of drainage and sewer pipe are not produced for others. It is beyond the scope of this book to discuss all the possible types of drainage and sewer pipe fittings. We will discuss some of the more common ones used in modern residential plumbing. Read the full Topic

Drain and Sewer Pipe Materials, Fittings, and Joints

Drainage and Sewer Pipe Materials
1. You may use any of the common drain and sewer pipe materials listed in the following table. You may use other approved materials listed in the IRC.
2. Install galvanized steel pipe at least (≥) 6 inches above the ground.
3. Use ABS, PVC, cast-iron, or any other pressure-rated pipe from Table P3002.2 in forced main sewers. Forced main sewers are rare in residential construction.

Drain and Sewer Pipe Fittings General Requirements
1. Install fittings that have a smooth interior surface and are compatible with the pipe to which they are attached. Example: do not use ABS fi tt ings with PVC pipe.
2. Do not use fittings that contain ledges, shoulders, or reductions that may retard or obstruct drainage flow.
3. Install fittings that maintain a 2 percent slope and are approved for use where installed. Example: do not use a vent tee in a drainage pipe where water fl ows.

Drain and Sewer Pipe Prohibited Joints and Connections
1. Do not use threaded connections in pipes where the threads run on the inside of the pipe and could retard or obstruct drainage fl ow.
2. Do not drill, tap, burn, or weld drainage, sewer, and vent pipes. Example: do not drill into a vent pipe to insert the discharge hose from a water softener.
3. Do not use the following types of joints and connections: (a) cement or concrete, (b) mastic or hot-pour bituminous, (c) fittings not approved for the specific type of pipe or installation, (d) joints between different pipe diameters made with elastomeric rolling O-rings, (e) solvent-cement joints between different types of plastic pipe, and (f) saddle fittings.

ABS Plastic Pipe Joints
1. You may use approved elastomeric gaskets to join buried ABS pipes. Do not use elastomeric gaskets to join above ground ABS pipes unless the use is approved by the building official.
2. You may use solvent cement to join ABS pipes above and below ground. Clean and dry pipes and fittings before applying solvent cement to all joint surfaces. Make the joint while the solvent cement is wet. Use solvent cement that complies with ASTM D 2235. Do not use PVC cement with ABS pipe.
3. You may use threaded joints for Schedule 80 and heavier ABS pipe. The threads should be NPT type. Do not place threads on the pipe’s interior.

Cast-Iron Hub and Spigot Joints
1. You may use lead-caulked joints to join cast-iron hub and spigot pipes. Pack the joint firmly with oakum (hemp) and fill with molten lead at least (≥) 1 inch deep and not more than (≤) ⅛ inch below the rim of the hub. Pour the lead in one continuous operation. This method is rare in modern residential plumbing.
2. You may use an approved positive-seal one piece elastomeric compression gasket to join cast iron
hub and spigot pipes. Place the gasket in the hub before the spigot is inserted.

Cast-Iron Hubless Pipe Joints
1. Use an approved elastomeric sealing sleeve and stainless steel retaining rings to join cast-iron hubless pipes.

Copper and Brass Pipe and Copper Tubing Joints
1. You may braze joints in copper pipe and tubing and joints in brass pipe. Clean all pipes and fittings and use an approved flux where required. Copper and brass are rarely used as drain pipes in modern residential construction.
2. You may use approved mechanical joints to join copper pipe and tubing and to join brass pipes. Install the mechanical joints according to manufacturer’s instructions.
3. You may solder joints in copper pipe and tubing and joints in brass pipe. Soldering is the most common method of joining copper pipe and tubing and joining brass pipes. Soldering is sometimes called sweating. Cut pipe edges square. Chamfer (bevel) the outside of the pipe and ream the inside of the cut pipe. Clean all surfaces to be soldered to a bright finish. Apply flux to all surfaces to be soldered. Apply heat to both the fitting and to the pipe to be soldered. Apply solder when both the fitting and the pipe are near the same temperature and at or above the solder’s melting point. Use solder with not more than (≤) 0.2 percent lead on potable water system pipes.

Steel Pipe Joints
1. You may use threaded joints for galvanized steel pipes. The threads should be NPT type.
2. You may use approved mechanical joints to join galvanized steel pipes. Install the mechanical joints according to manufacturer’s instructions.

PVC Plastic Pipe Joints
1. You may use approved elastomeric gaskets to join buried PVC pipes. Do not use elastomeric gaskets to join above ground PVC pipes unless the use is approved by the building official.
2. You may use solvent cement to join PVC pipes above and below ground. Clean and dry pipes and fittings before applying primer to all joint surfaces. Apply primer that complies with ASTM F656. PVC primer is often purple, but doesn’t need to be purple unless required by your local jurisdiction. Apply solvent cement that complies with ASTM D 2564. Make the joint while the solvent cement is wet. Do not use ABS cement with PVC pipe.
3. You may use threaded joints for Schedule 80 and heavier PVC pipe. The threads should be NPT type. Do not place threads on the pipe’s interior.

Joints Between Different Types of Pipe
1. Use compression or mechanical-sealing elastomeric fittings approved for joining the different types of pipe. Install all fittings according to manufacturer’s instructions.
2. Use an approved brass ferrule with a caulked joint or a mechanical compression joint when joining copper tubing to cast-iron pipe.
3. Use a brass converter fi tt ing or a dielectric fi tt ing when joining copper tubing to galvanized steel pipe.

Toilet (Closet) Flange Joints
1. Install a closet flange that is firmly attached to a structural support (floor) to connect a toilet to drainage piping. Use a closet flange that is compatible with the connected drainage pipe. Example: do not use a PVC closet flange with ABS pipe. Do not use the closet flange to provide structural support to the toilet.
2. Use non-corrosive bolts and an approved gasket (O ring) or other approved setting compound to secure the toilet and closet flange and to make the seal water tight.
3. You may use a waste connector and sealing gasket instead of a closet flange. Secure the waste connector to a solid and firm base and install the waste connector and gasket according to manufacturer’s instructions.

Drain and Sewer Pipe Size

Limitations of the Material in this Section
Determining the correct size of drain and sewer pipes requires knowledge that is beyond most readers of this book; therefore, we will not discuss in detail how to determine drainage and sewer pipe sizes. Leave calculation of correct drain and sewer pipe size calculations to qualified contractors. We will present some basic information about how to calculate drain and sewer pipe sizes and present an example of calculating drainage and sewer pipe sizes for an average home. Do not assume that your drain and sewer pipe sizes are wrong if your home has different size pipes from the following example. Your pipes may have been sized using different assumptions or sizing methods. In practice, plumbers often use “rules of thumb” to install drain and sewer pipes using a limited number of pipe sizes that may be larger than the minimum required size. This makes drain and sewer installation easier and relieves the plumber from performing detailed pipe size calculations. Read the full Topic

Gray Water Recycling Systems

1. Refer to IRC Section P3009 for information about capturing water from sinks, bathtubs, showers, and clothes washing machines for use in flushing toilets and in landscape irrigation systems.

Sewage Pumps and Ejectors

Sewage Pump and Ejector Installation
1. Drain only plumbing fixtures located below the building sewer into a sewage pump or ejector. Drain all other plumbing fixtures into the building sewer. You may drain plumbing fixtures located above the building sewer into a sewage pump or ejector when you install a sewage pump or ejector in an existing plumbing system.
2. Use PVC, CPVC, copper, brass, ductile iron, or PE pipe and fittings on the discharge side of sewage pumps and ejectors. Read the full Topic