http://www.legislation.gov.uk/id/uksi/1977/167

SCHEDULE 1Standards for pressure heaters

(Regulation 14(1) and (2))

PART I

Pressure heater fuel container pressures

1.

An internal pressure of 2.1 bar.

2.

Any internal pressure capable of being produced by operating the pump connected to the container through sixty complete strokes in one minute with the container full to the full fuel level.

3.

The lesser of the two pressures calculated in accordance with the formulae set out in Part III of this Schedule.

PART II

Pressure heater burner pressures

1.

An internal pressure of 4.2 bar.

2.

An internal pressure equal to any capable of being produced in the fuel container of the heater by operation of the pump in the manner described in Part I of this Schedule.

3.

An internal pressure equal to the lesser of the two pressures calculated, in relation to the fuel container of the heater, in accordance with the formulae set out in Part III of this Schedule.

PART III

Formulae for calculating pressures

Pressure 1 in bars = \frac{1330 \times the mechanical advantage}{the internal cross-sectional area of the pump in millimetres}

Pressure 2 in bars = 1.03 \times the compression ratio of the pump.

In this Part of this Schedule “the mechanical advantage” means the factor by which the force applied to the pump handle is multiplied between the point at which the force is applied and the pump piston.