Question

The plumbing system in which anti siphonage pipe is provided only for solid waste line is % "Anti siphonage pipe" refers to vent pipes or anti-siphon traps designed to prevent the siphoning of water seals in traps.

• A. Partially ventilated single stack system
• B. Two pipe system
• C. Single stack system
• D. One pipe

Hint:

Plumbing drainage systems:
\textbf{Two-pipe system:} Separate soil and waste stacks, both usually fully vented.
\textbf{One-pipe system (Single Stack):} Combines soil and waste into one stack.
\textit{Fully ventilated (Modified One-Pipe):} Most/all traps have anti-siphonage vent pipes.
\textit{Partially ventilated:} Only selected critical traps (e.g., WCs handling solid waste) are provided with anti-siphonage vent pipes. Other traps might rely on main stack vent, resealing traps, or air admittance valves.
\textit{Unventilated:} Minimal or no branch venting (relies on main stack vent).
Providing anti-siphonage (vent) pipes "only for solid waste line" fixtures (like WCs) is characteristic of a \textbf{partially ventilated single stack system}.

Answer 1

The Correct Option is A

Plumbing drainage systems are designed to carry away wastewater and prevent sewer gases from entering buildings. This involves soil pipes (for foul water from WCs, urinals), waste pipes (for sullage from sinks, baths, showers), and vent pipes (to maintain atmospheric pressure in the system and protect trap seals). Different plumbing systems:
Two-pipe system: Separate pipes for soil (foul water) and waste (sullage). Both soil pipe and waste pipe have their own separate vent pipes (or are connected to a common vent stack). This is the most elaborate and traditionally considered the most hygienic system, but also more expensive.
One-pipe system (Single stack, partially ventilated):
Single stack system (fully ventilated or modified one-pipe): A single main vertical pipe (stack) collects both soil and waste water. This stack is extended upwards as a main vent. Traps of all appliances connected to this stack are individually ventilated by separate branch vent pipes connecting to a common vent stack or back to the main soil/waste stack above the highest connection (if it also serves as vent).
Single stack system (unventilated or simplified): A very basic system where traps rely solely on their own water seal and the main stack vent for protection. Prone to siphonage or back pressure if not carefully designed; generally not recommended for multi-story buildings without specific anti-siphon traps or air admittance valves.
Partially ventilated single stack system (or One-pipe system with partial ventilation): This is a variation of the one-pipe system. It aims to simplify ventilation compared to a fully ventilated one-pipe or two-pipe system. In some forms of partially ventilated single stack systems, only the traps of certain appliances, particularly those carrying solid waste (like WCs), are provided with dedicated anti-siphonage pipes (branch vents), while other less critical fixtures (like sinks or baths carrying only liquid waste) might rely on the main stack vent and careful pipe sizing to protect their traps, or use resealing traps or air admittance valves. The description "anti siphonage pipe is provided only for solid waste line" (meaning fixtures connected to the soil pipe branch carrying solid waste, primarily WCs) fits this concept of selective or partial ventilation. The "solid waste line" itself is the soil pipe which is part of the single stack. Let's re-evaluate options based on the specific phrasing: "anti siphonage pipe is provided only for solid waste line".
(a) Partially ventilated single stack system: This system, by definition, implies that not all traps are individually vented. Providing anti-siphonage pipes (vents) specifically for critical fixtures like WCs (which handle "solid waste") while possibly omitting them for others (or using alternative protection) is a form of partial ventilation within a single stack setup. This seems to fit the description best.
(b) Two pipe system: In a full two-pipe system, both the soil pipe and the waste pipe typically have comprehensive ventilation.
(c) Single stack system: This term can be ambiguous. If it means a "fully ventilated single stack system" (modified one-pipe), then most/all traps are vented. If it means an "unventilated single stack", then few or no anti-siphonage pipes are used beyond the main stack vent. "Partially ventilated" is more specific.
(d) One pipe: "One-pipe system" is a broad category that includes fully ventilated (modified one-pipe) and partially ventilated single stack systems. Option (a) is more specific. Given the specific detail "only for solid waste line", the Partially ventilated single stack system is the most accurate description. \[ \boxed{\text{Partially ventilated single stack system}} \]