Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2021

Property, plant and equipment

Schedule of elements of property, plant and equipment

Elements of property, plant and equipment are as follows:

					Estimated
December 31,	2021		2020		Lives
(in thousands)
Property, plant and equipment
- Land	$	1,255	$	1,255
- Land improvements		319		319	6-10 years
- Buildings		1,446		1,446	25-39 years
- Building improvements		3,099		3,072	25-39 years
- Cylinders		13,272		13,624	15-30 years
- Equipment		26,653		25,138	3-10 years
- Equipment under capital lease		315		315	5-7 years
- Vehicles		1,773		1,537	3-5 years
- Lab and computer equipment, software		3,103		3,103	2-8 years
- Furniture & fixtures		837		679	5-10 years
- Leasehold improvements		852		852	3-5 years
- Equipment under construction		930		944
Subtotal		53,854		52,284
Accumulated depreciation		33,761		30,374
Total	$	20,093	$	21,910