Grease Separator Selection Guide for Hotel Kitchens India

Grease Separator Selection Guide for Hotel Kitchens

Grease separators (also called grease traps or grease interceptors) are mandatory in all commercial kitchen drainage systems in India. Without them, cooking fats, oils, and grease (FOG) accumulate in the drainage network, causing blockages, odour complaints, rodent infestation, and sewage backups. For hotels with multiple F&B outlets, proper grease separator selection and maintenance is a critical operational requirement.

1. Why Grease Separators Are Mandatory

• Grease solidifies at temperatures below 40°C, rapidly coating drain pipe walls
• FOG causes blockages in both the hotel’s internal drainage and the municipal sewer network
• CPCB (Central Pollution Control Board) regulations prohibit discharge of grease-laden wastewater to sewers
• Most municipal sewerage bylaws in Indian cities specify grease trap requirements for commercial kitchens
• STP (Sewage Treatment Plants) are severely impacted by FOG — destroys biological treatment efficiency

2. Types of Grease Separators

3. Sizing Method — PDI Standard (Plumbing and Drainage Institute)

The standard method for sizing grease traps is based on the peak dishwasher flow rate and the number of meals served. The PDI G101 standard (widely adopted in India) uses the following approach:

Step 1 — Determine Total Flow Rate

• Sum up all appliances draining to the grease trap: dishwashers, pot sinks, floor drains, prep sinks
• For each appliance, note the flow rate from manufacturer data sheets
• Do not include toilet/urinal drainage — this goes directly to the main sewer

Step 2 — Apply Retention Time

• Standard retention time: 2.5 minutes for grease separation to occur
• Grease trap capacity (litres) = Total flow rate (L/min) × retention time (2.5 min)

Step 3 — Apply Diversity Factor

• Not all appliances run simultaneously — diversity factor 0.6–0.8 for hotel kitchens

Sizing Example — 200-Room Hotel, 2 F&B Outlets

4. Indian Standards and Compliance

• IS 6618: Code of practice for installation and maintenance of grease traps
• CPCB guidelines: FOG content in discharge must not exceed 50 mg/L
• NBC 2016 Part 9: Plumbing services — references grease trap requirement for commercial kitchens
• Most state PCB consent conditions for hotels specify grease trap installation and maintenance records

5. Installation Requirements

• Locate grease trap as close to the source (kitchen) as possible — before any connection to main sewer
• Install access covers — sized for manual cleaning (minimum 600×600 mm for large traps)
• Vent grease trap separately — do not connect vent to kitchen exhaust ventilation
• Provide hot water inlet for manual cleaning — reduces grease viscosity
• Install sampling chamber downstream for effluent monitoring
• For large volume GRP/concrete interceptors — install level indicator and high-level alarm

6. Maintenance Schedule