Nocchi Pressure Units Selection L

Summary

Product identification

This document provides a guide for the selection of Nocchi Pressure Units and Pressure Boosters.

Operating limits

• A minimum pressure at the topmost valve of 1.5 ATM is envisaged in the selection tables.

Mechanical / hydraulic

Selection of a pressure unit requires consideration of two essential factors:

• The required flow rate at the peak time of use.
• The total manometric head.

The required flow rate can be determined using statistical average diagrams (see the official PDF for Fig. 1), which include data for:

• Apartments (Number of persons, % Calculated simultaneous mode)
• Bends for WC with enclosures (for WC with rapid routers + 30%)
• Offices
• Hotels
• Homes
• Large Department Stores
• Communities

The total manometric head corresponds to the minimum operating pressure of the unit and is calculated based on the supply source:

Case (A) Supply from a deposit located on the same level as the unit:

• Add the height of the highest collection point to the pressure required at that point, plus any relevant pressure drops.
• Example: Building H 18 m + Minimum pressure 15 + Pressure drops 2 = 35 Meters.

Case (B) Supply from an aqueduct or deposit located on a level above the unit:

• Start with the value obtained from Case A, then subtract the specific pressure of the aqueduct or that generated by the drop from the deposit.
• Example: Required head 35 - Aqueduct pressure 20 = 15 Meters.
• Example: Required pressure 35 - Tank 20 = 15 Meters.

Case (C) Supply from a well or deposit located on a level below the unit:

• Start with the value obtained from Case A, then add the value in meters between the water level and the unit.
• Example: Required head 35 + Suction H 5 = 40 Meters.

Pressure Drops in Pipelines The document includes tables for calculating pressure drops in new galvanized pipelines, based on flow rate and nominal pipe diameter.

• Large figures in the table represent pressure drops per 100 m of pipeline.
• Small figures in the table represent the speed of water in m/second.
• Nominal diameters are provided in inches and millimeters (e.g., 1/2" / 15.75 mm, up to 6" / 155.50 mm).
• Flow rates range from 0.6 m³/h (10 L/min, 0.16 L/sec) up to 300 m³/h (5000 L/min, 83.3 L/sec).

See the official PDF for exact tabulated values.

When assessing pressure drops in pipelines constructed in other materials, the value obtained for galvanized pipe should be multiplied by the following fixed coefficients:

• 0.6 for PVC pipes
• 0.7 for aluminum pipes
• 0.8 for sheet steel pipes
• 1.3 for cement fiber pipes

Disclaimer: This summary is based on extracted text and may not include all figures, footnotes, or the latest revisions from the original OEM PDF. Contractual data must always match the specific OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror