Steam trap classification

This standard is equivalent to the international standard ISO 6704:1982 titled "Steam trap classification."

1. Scope and Field of Application

This standard outlines the fundamental classification of steam traps. It applies specifically to the classification of the opening and closing mechanisms, regardless of the specific structural design of the device.

2. Definitions

2.1 Steam Trap

A steam trap is an automatic control device that automatically discharges condensate from a closed system containing steam while ensuring no loss of live steam. It also allows for controlled steam flow when necessary.

3. Classification

Based on the driving mechanism of the opening and closing component, steam traps can be categorized into three main types:

a) Mechanical steam traps, which operate based on changes in condensate level (see 3.1).

b) Thermostatic steam traps, which are activated by temperature variations in the condensate (see 3.2).

c) Thermodynamic steam traps, which function using the dynamic behavior of the condensate (see 3.3).

Schematic Diagram	Principle of Operation
3.1 Mechanical Steam Trap 3.1.1 Closed Float Steam Trap	The movement of the opening and closing element is triggered by the change in the condensate level inside the casing.
3.1.2 Open Float Steam Trap	The rising or falling of the condensate level in the float causes the opening and closing mechanism to activate.
3.1.3 Inverted Bucket Steam Trap	The condensate level within the float triggers the opening and closing of the valve.
3.2 Thermostatic Steam Trap 3.2.1 Pressure-Driven Steam Trap	The opening and closing member is actuated by the pressure difference between the condensate and the vapor pressure of a deformable element.
3.2.2 Bimetallic or Thermoelastic Steam Trap	The bimetallic or thermoelastic element deforms due to temperature changes in the condensate, causing the opening and closing action.
3.2.3 Solid or Liquid Expansion Steam Trap	The component with a high thermal expansion coefficient moves as the condensate temperature changes, thus operating the valve.
3.3 Thermodynamic Steam Trap 3.3.1 Disc Steam Trap	The opening and closing action is caused by the pressure difference between the inlet and the pressure chamber.
3.3.2 Pulse Steam Trap	The opening and closing mechanism is triggered by the pressure difference between the inlet and the pressure chamber.
3.3.3