Drainage Systems PDF

DRAINAGE SYSTEMS ENGR. VINCE IVAN ILAGAN INTENDED LEARNING OUTCOME At the end of this topic, the students will be able to: 1. Identify and apply relevant plumbing codes and regulations. 2. Design basic drainage systems and select appropriate components. 3. Perform calculations, create pla...

DRAINAGE SYSTEMS ENGR. VINCE IVAN ILAGAN INTENDED LEARNING OUTCOME At the end of this topic, the students will be able to: 1. Identify and apply relevant plumbing codes and regulations. 2. Design basic drainage systems and select appropriate components. 3. Perform calculations, create plans, and troubleshoot drainage systems. Drainage System Includes all the piping within public or private premises, which conveys sewage or other liquid wastes to a legal point of disposal, but does not include the mains of a public sewer system or a public sewage treatment or disposal plant. This system is often known as the DWV System (Drainage, Waste and Vent). The complete drainage system is subdivided into four (4) sub-systems, as follows. Drainage System 1. SOIL DRAINAGE SYSTEM The piping that conveys the discharge of water closets or fixtures having similar functions (containing fecal matter), with or without the discharges from other fixtures. 2. WASTE DRAINAGE SYSTEM The piping that receives the liquid discharge, from plumbing fixtures other than those fixtures (water closets) receiving fecal matter. This piping is free of fecal flow. Drainage System 3. VENT SYSTEM the piping system that receives a flow or air to or from a drainage system or to provide a circulation of air within such system to protect trap seals from siphonage or back pressure. 4. STORM DRAINAGE SYSTEM The piping system that receives clear water drainage from leaders, downspouts, surface run-off, ground water, subsurface water, condensate water, cooling water or other similar discharges and conveys them to the point of disposal. All sanitary wastes must be excluded. Sanitary Drainage System: Components Trap ➤ a fitting or device designed and constructed to provide when properly vented, a liquid seal which prevents the backflow of foul air or methane gas without materially affecting the flow of sewage or waste water through it. Branch ➤ any part of the piping system other than a main, riser or stack Stack- ➤ the vertical main of a system of soil, waste or vent piping extending through one or more stories. Sanitary Drainage System: Components House/Building Sewer ➤ extends from the house drain at a point 0.60m from the outside face of the foundation wall of a building to the junction with the street sewer or to any point of discharge, and conveying the drainage of one building site. House/Building Drain ➤ part of the lowest horizontal piping of a plumbing system which receives the discharges from the soil, waste and other drainage pipes inside the building and conveys it to the house sewer outside of the building. Sanitary Drainage System: Components House Trap / Building Trap ➤ is defined as a device installed in the house drain immediately inside the foundation wall of the building. It serves as a barrier and prevents the gases coming from the public sewer or septic tank in circulating through the plumbing system. Sanitary Drainage System: Components Septic Tank ➤ A watertight receptacle which receives the discharge of a drainage system or thereof, designed and constructed so as to retain solid, digest organic matter through a period of detention Private Sewage Disposal System ➤ a septic tank with the effluent discharging into a subsurface disposal field, seepage pits or of such other facilities or may be permitted by the plumbing code.. Sanitary Drainage System: Unit of Measurement Unit of Measurement of Sizes of Sanitary Drainage Lines The size of waste pipes or soil pipes depend on the amount of waste it carries. A lavatory discharges 0.47 liter/sec or 28.3 liters/min (7.48 gallons per min or 1 cu ft per min), which is equivalent to one Fixture Unit (F.U.)  Fixture Quanti FU ty EXAMPLE Water Closet Third Floor 3 FIRST FLOOR (Public use) Lavatory 3 Water closet (Flushometer VALVE) 1.6 GPF Floor Drain– 3 pcs 3 Lavatory – 3 pcs Total Floor Drain – 3 pcs Second Floor Water Closet 3 SECOND FLOOR Lavatory 3 Water closet (Flushometer VALVE) 1.6 GPF Floor Drain– 3 pcs 3 Lavatory – 3 pcs Total Floor Drain – 3 pcs First floor Water Closet 3 THIRD FLOOR Lavatory 3 Water closet (Flushometer VALVE) 1.6 GPF – 3 pcs Floor Drain 3 Lavatory – 3 pcs Total Floor Drain – 3 pcs TRAPS DRAINAGE SYSTEM Types of Permissible Traps: The Common P-Trap Used for lavatories, kitchen sinks, laundry tubs, & urinals. Materials commonly used for the P-trap: nickel, chrome plated brass, Galvanized malleable copper, & PVC. The Deep Seal P-Trap Water seal is about twice the size of the common Ptrap, used for extreme conditions because resealing quality is greater Types of Permissible Traps: The Stand Trap ➤ Used for fixtures such as slop sinks that are usually built low in the ground, leaving very little space for a foundation & a trap. Serves as a water seal & structural support for the fixture. Types of Prohibited Traps: The S Trap ➤ Predecessor of P-traps ➤“S” trap will easily siphon or suck water out from the trap which will end up releasing methane (sewer) gases into the home. Types of Prohibited Traps: The Bell Trap ➤ The Bell Trap Drain is designed to be used in the garage, on the balcony, or anywhere else outside. ➤ bell traps fail due to their vulnerability to drying out and potential for accumulating decaying, organic debris. Types of Prohibited Traps: The Crown Vented Trap ➤A crown-vented plumbing trap is an S-trap to which is added an air vent connected at or near the uppermost crown of the S. ➤Heavy flow down the drain could briefly backup into the crown, and debris would collect there over time, eventually clogging the vent. Types of Trap for Special Conditions The Running Trap ➤Used within the line of the house drain. "U"- shaped trap. Types of Trap for Special Conditions The Drum Trap ➤Has a large diameter (around 0.16 m), used for fixtures that discharge large amount of water (bathtubs, shower or floor drains) Types of Trap for Special Conditions ➤No fixture shall be double- trapped ➤No trap shall be installed without a vent. ➤ Building trap shall not be installed except where required by the authority having jurisdiction. Each building trap when installed shall be provided with a cleanout and with a relieving vent or fresh- air intake on the inlet side of the trap. Types of Trap for Special Conditions ➤No fixture shall be double- trapped ➤No trap shall be installed without a vent.  GENERAL CONSIDERATION DRAINAGE SYSTEM Grade Of Horizontal Piping ⮚ Drainage pipes shall be run in practical alignments & at a uniform slope of not less than 20mm/m or 2% toward the point of disposal. If it is impracticable to obtain such slope due to the following conditions: Grade Of Horizontal Piping ⮚ If it is impracticable to obtain such slope due to the following conditions: Excessive depth of the proposed drainage line Existing adverse in arrangements of building structure Any such pipe or piping 102mm or larger in diameter may have a slope of 10mm/m or 1% provided it is approved by Administrative Authority. Grade Of Horizontal Piping ⮚ If it is impracticable to obtain such slope due to the following conditions: Structural and/or geological features of the terrain Changes in direction of Drainage flow ⮚ Changes in direction of piping shall be made by the use of approved pipe fittings & shall be the angles presented by: ⮚ 22 1/2 degrees bend (1/16) bend ⮚ 45 degrees bend (1/8) bend ⮚ 60 degrees bend (176) bend or other approved fittings of longer sweeps. Sanitary Fittings Changes in direction of Drainage flow Horizontal to Vertical 45-degree wye branches 60-degree wye branches Combination of-45 degree & 1/8 bend branched Sanitary tee Double Sanitary tee Changes in direction of Drainage flow Horizontal to Horizontal 45-degree wye branches Combination of-45 degree & 1/8 bend branched Or other approved fittings of equivalent sweep Changes in direction of Drainage flow Vertical to Horizontal 45-degree wye branches Combination of-45 degree & 1/8 bend branched Or other approved fittings of longer sweep 60-degree branches or offsets (only for pipes intalled in true vertical position)  PROTECTION OF PIPE MATERIALS AND STRUCTURES DRAINAGE SYSTEM Protection of Piping ⮚ The bottom of all pipe trenches deeper than the footing of any adjacent building or structure & Parallel to it must be at least 45 degrees. Protection of Piping ⮚ All pipings passing under or through walls shall be protected from breakage with embedded metal pipe sleeves ⮚ Void between pipes & sleeves through concrete floors in the ground shall be appropriately sealed with bitumen. The bottom of all pipe trenches deeper than the footing of any adjacent building or structure HANGERS AND SUPPORTS DRAINAGE SYSTEM Hangers and Supports Hangers and Supports Hangers and Supports: Vertical Piping ⮚ Cast Iron Soil Pipe - Bell & Spigot & Hubless pipe shall be supported at every storey or closer. Base and each floor not to exceed 15 feet (4,572mm) ⮚ Screwed Pipe- Iron Pipe Size (IPS) shall be supported at not less than every other storey height. (maximum of 25 feet (7,620mm) Hangers and Supports: Vertical Piping ⮚ Copper Tubing - shall be supported at each storey or at a maximum intervals of 3m o.c. ⮚ Lead Pipe - shall be supported at intervals not exceeding 1.20m at centers ⮚ Platic Pipe (PVC, ABS, CPVC, & PP)- Base and each floor. Hangers and Supports: Horizontal Piping ⮚ Suspended cast iron soil pipe shall be supported at not more than 1.5m intervals, except that pipe exceeding 1.5m length may be supported at not more than 3m intervals. ⮚ Hubless or compression gasket joints must be supported at least every other joint except that when the developed length between supports exceeds 1.2m, they shall be provided at each joint.