Sentence: Notwithstanding the use of special assembly techniques, it is currently quite common to find, downstream of the assembly line, known radiator caps with the small <e1>spring</e1> of the low-pressure <e2>valve</e2> imperfectly aligned with one of its necessary bearing surfaces and/or with the shutter, which leads to unpredictable operation of the radiator cap and consequent rejection of the product.
Entity 1 type: Object
Entity 2 type: Object