Compression spring balance manual loading arm has peculiar features as easy handling, light weight, easy contraposition; the structure is designed as compression spring balance configuration so as to save room for trestle and keep balance at any position in normal operating range; easy manual-operation, good seal, ideal equipments for manually top loading of light oil, mazout or other chemical liquids into train tanker or tank truck etc. Technical parameter 1. Nominal diameter : DN50~DN100 2. Nominal pressure: 1.6MPa 3. Applicable media: clean oil, mazout, lubricants, chemical liquids