M'dziko lovuta kwambiri la machitidwe owongolera madzimadzi, magwiridwe antchito ndi mphamvu ya mavavu agulugufe zimatengera kusankha kwa zida zopangira mipando. Nkhaniyi ikufotokoza za kusiyana pakati pa zinthu ziwiri zomwe zimagwiritsidwa ntchito mu izi
(Mafotokozedwe achidule) Kusamala kwa kukhazikitsa ndi kukonza ma valves a chitetezo: Kusamalira makina otetezeka: (1) valani ya chitetezo chokhazikika: