The one I currently have is a 5 gallon, is this ok to replace with?

They don't rate these things by the gallon in particular, although this size will just fit into a 5 gallon pail. I believe the actual model number is roughly equal to the cubic feet of water within the system. (boiler, heat coils, radiators, pipes, etc) This is a common size for the typical 2,000 - 3,000 sq ft home with a hot water boiler rated around 150,000 - 175,000 BTUs. A smaller home with old fashion cast iron radiators instead of baseboard will need this size expansion tank due to the extra water in the system. If you have to fudge, the extra size doesn't hurt if you have the room.BTW, the comment on the BTUs of the boiler has more to do with the typical size / water capacity than anything else. There are "low mass" (read: small physical size) boilers than only hold a few gallons of water, which is much less than the usual 20 gallons or more for an old school system.

This tank shows a 4.4 gallon capacity.....

How long should a tank like this (Amtrak extol expansion tank) last. What is its estimated life?

Mine lasted almost exactly 2 years. Then a tiny pinhole leak on the outer part of tank started spraying water everywhere.

Does this replace a vent rite vr30f? how hard to replace?

It should be a direct replacement for any tank with a 1/2" male thread and similar exterior dimensions. (roughly 11" height x 11" width) It's not difficult at all provided you read the other questions / replies on this product to get a feel for what else you may need to do. I know myself and a few others posted detailed instructions a few months back. Remember that proper diagnosis is key for resolving the problem and there are several posts on how to figure out if the tank is actually the issue.

OEM part number	102-1
Global Trade Identification Number	00642031113061
UPC	642031395726 642031113061 784497649729
Manufacturer	Amtrol
Product Dimensions	27.94 x 27.94 x 38.1 cm; 3.61 kg
Item model number	Amtrol 102-1 #30
Manufacturer part number	102-1
Item Weight	3.61 kg

AmtrolEX-30 30 Extrol Expansion Tank by Amtrol

Details

Description

Specifications

Common Questions