Dholera Industrial Water Supply Pipe Diameter: DICDL Mains

1. DICDL Potable Water Distribution Pipe Sizing Hierarchy

The municipal potable water network originates from the 150 MLD Water Treatment Plant (WTP) at Kanatal and branches across Town Planning (TP) schemes through standardized pipe dimensions:

2. Pipe Material Specifications and Internal Coating Standards

Due to the saline, sulfate-rich marine clay soils present across the Gulf of Khambhat basin, DICDL mandates rigorous corrosion-resistant coatings for all buried pipes:

• Internal Lining: All Ductile Iron water supply pipes must be centrifugally lined at the foundry with Portland Cement Mortar (IS 11906 / ISO 4179) enriched with anti-sulfate additives, or polyurethane (PU) barrier lining to prevent internal encrustation and maintain a Hazen-Williams roughness coefficient of $C \ge 140$.
• External Protective Coating: Pipes must receive an external metallic zinc spray coating with a minimum mass of 200 g/m², followed by a heavy finishing layer of bituminous paint or two-pack epoxy coating (minimum 100 microns dry film thickness) in accordance with BS EN 545.
• Joint Flexibility: Buried pipes utilize flexible push-on rubber gasket joints (Tyton-type conforming to IS 5382) that accommodate up to 3° to 5° of angular deflection, ensuring pipe integrity against seasonal ground swelling and settlement in marine clay.

3. Industrial Plot Service Connection Sizing Formula

Factory developers applying for an industrial water connection through the DICDL single-window portal must calculate their required service tap diameter ($d$) based on permissible pipeline flow velocities:

$$Q = A \times v = \frac{\pi \times d^2}{4} \times v$$

Where: * $Q$ = Design volumetric flow rate ($\text{m}^3/\text{sec}$), derived from peak factory consumption plus storage replenishment schedules. * $v$ = Velocity of flow in the connection pipe. DICDL engineering codes restrict connection pipeline velocity to a range of 1.0 m/s to 1.8 m/s to prevent water hammer surges and excessive friction head loss. * $d$ = Inside diameter of the tapping pipe in meters.

Solving for the tapping diameter:

$$d = \sqrt{\frac{4 \times Q}{\pi \times v}}$$

For example, a high-tech manufacturing plant requiring $150\text{ m}^3/\text{hr}$ ($0.0417\text{ m}^3/\text{s}$) at an optimal design velocity of $1.5\text{ m/s}$ requires:

$$d = \sqrt{\frac{4 \times 0.0417}{\pi \times 1.5}} = \sqrt{0.0354} \approx 0.188\text{ meters} \implies \text{DN 200 mm Service Tap}$$

4. Boundary Metering Chamber and Pressure Management

Under DSIRDA building codes, the interface between the DICDL municipal main and the plot interior must feature a standardized Boundary Metering Chamber:

1. Chamber Location: The reinforced masonry or RCC meter chamber must be situated within 1.5 meters of the front plot entrance gate, fully accessible to DICDL utility technicians from the road.
2. Instrumentation: The chamber houses an isolation butterfly valve, an inline Y-strainer, a dual-chamber air release valve, and a DICDL-approved Automated Meter Reading (AMR) ultrasonic flowmeter transmitting consumption data via NB-IoT or optical fiber to the ABCD Building command center.
3. Pressure Sustaining / Reducing Valve (PRV): To protect the factory’s private storage tank from pressure surges, a hydraulic PRV must be installed to regulate downstream pressure to an operating limit of 2.0 to 2.5 bar.
4. Air Gap Isolation: Direct boosting from the municipal connection using suction booster pumps is strictly prohibited. The municipal pipeline must discharge freely into an on-site underground sump with an atmospheric air gap of at least 150 mm above the tank overflow weir.

Frequently Asked Questions (FAQ)