Marvel

Marvel Gauge Glass Washers are seals for the tubular gauge glass on a boiler's water gauge. A washer sits between the glass and the packing nut of the gauge valve, where it closes the gap the nut alone cannot.

BoilerSupplies.com carries Marvel Gauge Glass Washers as a single family on the Marvel page. The washer is ordered by one measurement, the outside diameter of the gauge glass it seals. Have that diameter in hand, along with the number of glasses being changed.

Key facts

• BoilerSupplies.com lists one Marvel product family, Marvel Gauge Glass Washers.

• A gauge glass washer seals a tubular gauge glass at the packing nut of the gauge valve.

• Gauge glass washers harden with heat in service.

• Gauge glass washers are changed when the gauge glass is changed.

• A gauge glass washer is ordered by the outside diameter of the glass.

Is a gauge glass washer the same as a sight glass gasket or gauge glass packing?

Not always, though buyers use those names for it. Gauge glass washer and sight glass washer mean the seal at the ends of a tubular gauge glass. Gasket and packing get used for the same spot, but they can also mean other parts, so give the outside diameter of the glass with the order. BoilerSupplies.com lists the part as Marvel Gauge Glass Washers.

How do I size a Marvel gauge glass washer?

Size a Marvel gauge glass washer by the outside diameter of the gauge glass. Add the number of gauge glasses being changed and the make of the gauge valves, where it is known. Laying the used washer beside a tape measure for a picture helps once the glass is out. With the diameter and the quantity, the order is straightforward.

Why does a gauge glass leak at the packing nut?

One common cause is a washer that has hardened. Washers harden with heat in service, which is why they are changed when the glass is changed. What to do about a leaking gauge is decided at the boiler, not at the counter. Marvel Gauge Glass Washers are ordered by the outside diameter of the glass.

Should gauge glass washers be replaced with the gauge glass?

Yes, washers are changed when the glass is changed. The old washers have hardened with heat by then, so they come off with the old glass. New Marvel Gauge Glass Washers go on with the new glass, sized to its outside diameter.

Give BoilerSupplies.com the outside diameter of the glass and the number of Marvel washers needed, at 1-770-957-9599 or toll free 1-800-780-3776.