COSC 325 Houston (Plumbing) Exam | Questions and Answers

COSC 325 Houston (Plumbing) Exam | Questions and Answers SS Sanitary Sewer ABS Black plastic material VTR vent through roof Primary Purpose of roof vent Let air into system What division is plumbing 22 Invert Depth elevation of the bottom inside of the pipe DW Domestic Water CPVC (chlorinated polyvinyl chloride) hot and cold water supply, off white color FDC Fire Department Connection Above ground pipe material Metal 1 CFH (Cubic Feet per Hour) 1000Btu/h OSHA requirement for fall protection 6 feet OSHA requirement for trenching 5 feet Wall thickness terms for copper Type L, K, M DWV abbreviation for drainage, waste, and vent. Found on "p" sheets What are the four groups of plumbing pipe and fitting material? Plastic, Copper, Cast Iron, Steel What is Expansion loop for? In plastic, provides an area for tubing to expand What plastic pipe is common for DWV? Schedule 40 ABS What is the max length of rigid plastic DWV pipe? 35' What is ABS typically used for? Sanitary drainage, vent, aboveground and underground storm water drainage. What is PVC used for? Sanitary drainage, vent, aboveground and underground storm drainage, water mains, and water service lines. COLD WATER ONLY What is cpvc used for? Typically used for HW and CW distribution, Fire sprinkler pipes, water distribution What is PEX used for? Water service piping, CW and HW systems, used commonly in residential Hangers typically take up ___ of labor cost 20% What is Copper pipe used for? Water supply, fire suppression, HVAC. Fairly rare. What is Cast-Iron no-hub and bell-and-spigot used for? aboveground and underground sanitary drain, vent, and storm water drainage. Bell and spigot typically underground Fittings for plastic piping? Cement, caps, compression fittings Fittings for Copper tubing? Solder joint fittings (Require fire watch), press fitting, Rolled groove joint fitting, threaded Fittings for Cast Iron Hub (Bell-and-Spigot) and no hub Steel piping Galvanized or black Wall thickness terms for plastic Schedule 20, 40, 80, Bigger number=thicker Wall thickness terms for Copper piping Type L, K, M. K is thickest, DWV is thinnest Wall thickness terms for galvanized steel Schedule 40, 80 Angle Valve Globe valve in which the inlet and outlet are at 90 degrees to each other. less resistance to water flow and reduce number of joints required Ball Valve Valve having a ball-shaped internal component with a hole through its center that permits water to flow through when aligned with the waterway. Butterfly Valve Control valve that uses a flat circular plate in a pipe that rotates 90 degrees across the cross section of the pipe to control the flow of water. Check Valve A valve that allows flow in one direction but prevents flow in the opposite direction. Pressure reducing valve A valve which maintains uniform pressure on its outlet side regardless of its pressure fluctuations on the inlet side above the pressure level. Usually installed near meters Water Meter A device used to measure the amount of water that goes through the water service. (Cubic Feet or Gallons) DFU Drainage Fixture Unit. Measure of probable discharge of wastewater and waterborne waste into the drainage system formulated in tests. What is the minimum diameter of building sewer? 4" What is the general slope for a vent? 1/8" per foot Grade/Pitch/Slope for drainage pipe Min of 1/4" per foot, Max of 3" per foot. Underground sewer sometimes not as steep Purpose of a cleanout allow access to the piping to remove stoppages and clean the interior Where should Cleanouts be installed? Front main: at the outside wall of the building at the connection of building sewer and drain Stack base: at the base of all vertical soil or waste stacks all 90 degree changes in direction every 50' on 3" and smaller horizontal drainage pipe; every 100' on 4" and larger horizontal and drainage pipe Stack Vent The extension of a soil or waste stack above the highest horizontal drain connected to the stack. Relief vent A vent with a function to provide circulation if air between drainage and vent system. How far should a vent terminal be located from openings? 10' Yoke vent A pipe connecting upward from a soil or waste stack to a vent stack for the purpose of preventing pressure changes in the stack Individual vent A pipe installed to vent, a fixture trap and w/c connects with the vent system above the fixture served or terminates in the open air Common Vent A single vent that ventilates multiple traps in the case of a back to back vent. Why must horizontal vents be sloped? so water cannot accumulate Main Vent (Vent Stack) A vertical vent pipe that provides air circulation to/from any part of a drainage system. Branches connect here. How far above the flood level rim of the highest fixture should a branch vent be? 6" Why are storm water and sanitary waste separated? Rain water takes up large volumes and sanitary must go to a treatment plant Purpose of roof drain receive rainwater and discharge into leader When are storm drain traps required? When roof drain body is within 10' of an opening Max water pressure allowed in buildings 80psi Purpose of a pressure-reducing valve to reduce the pressure of the MAIN system to a predetermined lower pressure in the SUBsystem. When street main fluctuates in pressure, water supply to building must be constant. GPM Gallons per minute. Quantity of fluid flow. WSFU water supply fixture units. Measure of the estimated water demand of a plumbing fixture Water closet mounting floor set and wall hung Max volume of water used for flushing wc 1.6 gallons per flush Flush tank a tank located above or integral with the water closet, urinal or similar fixtures for flushing or removing excrements in the fixture Flushometer valve is a device, which discharges a predetermined quantity of water into fixtures for flushing purposes and is actuated by direct water pressure Diaphragm flushometer valve flushometer valve in which a segmented diaphragm within the valve body controls the flushing water by equalizing pressure on both sides of the diaphragm Min clear space in front of WC 48"