Similar International Standards
ISO 4064-1:2014ISO (International Organization for Standardization)
HighCurrent
Water meters for cold potable water and hot water — Part 1: Metrological and technical requirements
Specifies metrological and technical requirements for hot water meters, serving as the primary international benchmark.
OIML R 49-1:2013OIML (International Organization of Legal Metrology)
HighCurrent
Water meters intended for the metering of cold potable water and hot water - Part 1: Metrological and technical requirements
Provides internationally harmonized legal metrology requirements, closely aligned with ISO 4064.
EN 14154-1:2005+A2:2011CEN (European Committee for Standardization)
HighCurrent
Water meters - Part 1: General requirements
European standard harmonized with ISO/OIML, covering general requirements for water meters including hot water.
ISO 4064-1:1993ISO (International Organization for Standardization)
HighWithdrawn
Measurement of water flow in closed conduits — Meters for cold potable water — Part 1: Specifications
The contemporary international standard when IS 13959 was formulated, likely serving as its basis.
Key Differences
≠IS 13959 uses older metrological classes 'A' and 'B' and flow rate terminology (Qmin, Qn, Qmax). Modern standards like ISO 4064 use a flow rate ratio (R=Q3/Q1) and terminology of Q1, Q2, Q3, Q4.
≠The Maximum Permissible Error (MPE) in the upper flow zone for hot water is ±2% in IS 13959, whereas ISO 4064 specifies a wider tolerance of ±3% for water temperatures above 30°C.
≠IS 13959 is limited to inferential (turbine) type meters, whereas ISO 4064 and OIML R 49 cover all metering technologies, including volumetric, electromagnetic, and ultrasonic.
≠Pressure loss requirements are defined differently. IS 13959 specifies a maximum of 1.0 bar (100 kPa) at Qmax, while ISO 4064 defines pressure loss classes (e.g., Δp 63, allowing a maximum loss of 63 kPa at the permanent flow rate Q3).
≠IS 13959 specifies a dual static pressure test of 1.6 MPa for 15 mins and 2.0 MPa for 1 min. ISO 4064 requires a single test at 1.6 times the Maximum Admissible Pressure (MAP), typically 1.6 MPa, for 15 minutes.
Key Similarities
≈Both standards establish requirements for meters intended to measure the volume of hot water for billing and monitoring purposes.
≈The Maximum Permissible Error (MPE) in the lower flow zone (from Qmin/Q1 to Qt/Q2) is ±5% in both the Indian and international standards.
≈Both mandate that materials coming into contact with hot water must be corrosion-resistant, non-toxic, and not impart any undesirable taste, odour, or colour to the water.
≈The concept of an endurance test to simulate long-term operational wear is a key requirement in both IS 13959 and the international standards to ensure sustained accuracy.
≈Both standards define a similar maximum working pressure (Maximum Admissible Pressure), commonly specified as 1.0 MPa (10 bar).