Randallman

I am a machine builder of small bench top automaton assembly machines and have not dealt much with dispensing of flammable liquids where (methanol) is used.

A machine was built to do this dispensing before I came on board with this company, I am now reviewing the design and have raised some questions about the safety of this machine as the customer has requested another machine like this one.

The machine dispenses small amounts of methanol contained in a one quart using a syringe type pump the methanol is channeled from a single line to the pressure port of a valve gang assembly, each valve is capable of being turned on separately or all at once to dispense methanol.

Here is the Kicker the reservoir pump, valves and distribution tubing all live
in the bottom of the machine along with the electrical controls, keep in mind this is a confined area of about 20 x 20 inches 6 inches high, my point is if there was a leak in a supply line or a spill the fumes could build up in the confined space and be ignited by the power on relay contacts small arc or some other point of ignition. The attitude of the designer is that the possibility is remote that this would ever occur. I don't think OSHA would agree, I would like to follow ANSI standards and also be EU compliant.

Anybody your thoughts.

wildleg

as machines age, leaks occur. The notion that "the likelihood is remote" seems naiive.

__________________
As President Roosevelt said: "We have nothing to fear but fear itself. And Chuck Norris. And 滿口胡言. And Grabthar's hammer. And Gort. and 江南 Style. and rotting in the street and Zombies . . . and Wayne Griffen "

Copper88

Maybe switch to an air-powered diaphragm pump. No sparks.

erics37

I don't know anything about the machine-building end of things, only the field wiring, but that kinda sounds more like a Class 1 Div 2 location. I don't know what ANSI and UL and all that would have to say about your machine, but NEC says this:

500.5(B)(2) Class I, Division 2. A Class I, Division 2 location is a
location
(1) In which volatile flammable gases, flammable liquid–
produced vapors, or combustible liquid–produced vapors
are handled, processed, or used, but in which the
liquids, vapors, or gases will normally be confined
within closed containers or closed systems from which
they can escape only in case of accidental rupture or
breakdown of such containers or systems or in case of
abnormal operation of equipment, or
(2) In which ignitible concentrations of flammable gases,
flammable liquid–produced vapors, or combustible
liquid–produced vapors are normally prevented by positive
mechanical ventilation and which might become hazardous
through failure or abnormal operation of the ventilating
equipment, or
(3) That is adjacent to a Class I, Division 1 location, and to
which ignitible concentrations of flammable gases,
flammable liquid–produced vapors, or combustible
liquid–produced vapors above their flash points might
occasionally be communicated unless such communication
is prevented by adequate positive-pressure ventilation
from a source of clean air and effective safeguards
against ventilation failure are provided.
Informational Note No. 1: This classification usually includes
locations where volatile flammable liquids or flammable
gases or vapors are used but that, in the judgment of
the authority having jurisdiction, would become hazardous
only in case of an accident or of some unusual operating
condition. The quantity of flammable material that might
escape in case of accident, the adequacy of ventilating
equipment, the total area involved, and the record of the
industry or business with respect to explosions or fires are
all factors that merit consideration in determining the classification
and extent of each location.
Informational Note No. 2: Piping without valves, checks,
meters, and similar devices would not ordinarily introduce
a hazardous condition even though used for flammable liquids
or gases. Depending on factors such as the quantity
and size of the containers and ventilation, locations used for
the storage of flammable liquids or liquefied or compressed
gases in sealed containers may be considered either hazardous
(classified) or unclassified locations. See NFPA 30-
2008, Flammable and Combustible Liquids Code, and
NFPA 58-2011, Liquefied Petroleum Gas Code.