DFU are used to determine the drainage from fixtures and required capacity of sewer service systems

DFU (Drainage Fixture Unit Values) is defined by the the Uniform Plumbing Code (UPC) and can be used to determine required drainage capacities from fixtures and their service systems.

A Fixture Unit is not a flow rate unit but a design factor based on the rate of discharge, time of operation and frequency of use of a fixture. A fixture unit is equal to one cubic foot of water drained in an 1 1/4 pipe over one minute (≈ 7.48 US gpm, ≈ 0.47 l/s).

Each system shall be identified with a colored pipe or band and coded with paints, wraps, and materials compatible with the piping. Except as required by Section 601.3.3, nonpotable water systems shall have a yellow background with black uppercase lettering, with the words 'CAUTION: NONPOTABLE WATER, DO NOT DRINK.' A Constant Pressure System operates with a home’s well pump and a variable frequency drive controller to automatically monitor household water demand. The variable frequency drive speeds up or slows down the pump depending on your household water requirement.

Fixture Units are used in plumbing design for both water supply (WFSU) and waste water (DFU).

• DESIGN OF SMALL WATER SYSTEMS 1. This manual provides guidance and criteria for the design of small water supply, treatment, and distribution systems. For the purpose of this manual, small water systems.
• WATER SUPPLY AND DISTRIBUTION SECTION 601 GENERAL 601.1 Scope. This chapter shall govern the materials, design and installation of water supply systems, both hot and cold, for utilization in connection with human occupancy and habi­ tation and shall govern the installation of individual water supply systems. 601.2 Solar energy utilization.

• Water Supply Fixture Unit - WFSU
  

Since the fixtures in a system are never used all at the same time, the total units (capacity) achieved by adding the numbers for all fixtures must be compensated for intermittent use if we want a realistic estimate of the total drainage load.

Related Topics

• Sanitary Drainage Systems - The purpose of a sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment

Related Documents

• Capacity of Sewer Pipes - Carrying capacity of sewer and wastewater pipes - gpm and liter per second
• Cast Iron Soil Pipes - Dimensions - Dimensions of cast iron soil pipes
• Cleanouts in Draining Systems - Cleanouts provides access to the sewer for rodding
• Cold Water Storage Capacity - Required cold water storage capacity - commonly used fixtures and types of buildings
• Cold Water Storage per Occupant - Cold water storage for occupants in common types of buildings as factories, hospitals, houses and more
• Drainage Fixtures - Unit Loads and Sanitary Piping - Maximum Drainage Fixture Unit - DFU - loads for sanitary piping
• Drains and Sewers - Drainage Fixture Units (DFU) connected to building drains and sewers
• Fixture Units and Required Trap Size - No. of fixture units and required trap sizes
• Fixtures and Trap Sizes - Recommended drain trap sizes for different types of fixtures
• Main Vents in Draining Systems - Vents in draining systems protects traps against pressure differences that could cause them to siphon or blow out
• Plumbing Codes - Plumbing or sanitation codes are a set of rules and regulations imposed by cities, counties or states
• Volume Flow in Sanitary Drainage Systems - Calculate expected load in sanitary drainage systems
• Water Supply - Fixture Units WSFU - WSFU is used to calculate water supply service systems

Tag Search

• en: drainage sewage fixture capacity unit values dfu

California’s economy and culture have always been shaped by the abundance or scarcity of water.

The Golden State’s economy, agricultural production, and population have grown to number one in the nation, largely in pace with the development of its water resources.

California receives 75 percent of its rain and snow in the watersheds north of Sacramento. However, 80 percent of California’s water demand comes from the southern 2/3 of the state.

As people flocked to the mild climate and agricultural richness of southern California in the late 1800s and early 1900s, it was quickly apparent that the region’s water supply wouldn’t support the swelling population. Several water projects were built to import the precious resource to Southern California and the Central Valley.

Central Valley Project

2.3 Storage Design Water Supply System

In the 1930s, the federal government got involved, building the Central Valley Project (CVP) to support the arid but fertile Central Valley and its agricultural economy. Built by the U.S. Bureau of Reclamation, the CVP transports water from Lake Shasta in the north to Bakersfield in the southern San Joaquin Valley.

2.3 Storage Design Water Supply Systems

State Water Project

California’s State Water Project (SWP) was constructed in the 1960s and 1970s to supply water to more than 27 million people and 750,000 acres of farmland. Planned, constructed,and operated by DWR, it is one of the world’s most extensive systems of dams, reservoirs, power plants, pumping plants and aqueducts and remains key to California’s economy. The Edmonston Pumping Plant, south of the Tehachapi Mountains, pumps water 1,926 feet up and over the ridge into Southern California, making it the world’s tallest water lift.

Colorado River

The Colorado Aqueduct, built in the 1930s, transports water from the Colorado River to Southern California. It's operated by the Metropolitan Water District of Southern California (MWD) and is the region’s primary source of drinking water.

Features & Considerations

The Delta

At the heart of California’s water system is the Sacramento-San Joaquin Delta. It's a natural feature of California’s hydrology, where the state’s two mighty rivers join and find their way to sea. It is also the export pool of the SWP, pumping water to millions of people in the San Francisco Bay Area, San Joaquin Valley, Central Coast, and Southern California.

Benefits

In addition to supplying water to farms, cities, and industry, the SWP provides flood control, recreational opportunities, and water for fish and wildlife. The SWP’s water storage facilities provide year-round recreation opportunities for communities and tourists. Lake Oroville, the SWP’s largest reservoir, was originally built in response to the Yuba City flood of 1955. It serves a critical function to prevent catastrophic flood damage in exceptionally rainy years.

Environment

California’s heavily engineered water system is blamed by many for declining fish populations, yet simultaneously praised by others for timely releases of cool water to sustain salmon, steelhead and other species. CVP and SWP pumps in the Delta operate under State and federal guidelines to reduce their effects on sensitive fish species. California continues to modernize its water system to increase water supply reliability while reducing impacts to wildlife and the state’s natural environment.

Sustainability

California has many competing needs for water. Cities, farms, and fish have been pitted against each other for more than a century in a 3-way tug-of-war for a sustainable supply of water. Sustainable groundwater management has been given a high priority as aquifers continue to be over pumped in many areas, particularly during dry periods when surface water to sustain agricultural yields is in short supply.

Infrastructure Investment

In order to maintain a reliable water supply, we must invest in our water system’s infrastructure. Infrastructure includes the aqueduct, canals, dams, spillways, reservoirs, levees, pumping plants, and more. Much of our infrastructure is aging and needs to be bolstered or reconstructed. New infrastructure plans are designed to ensure a reliable and sustainable water supply that supports our economy and our environment.