If no gaskets are used in the piping joints of a Freon system, the joints must be（）
A: finished joints
B: welded joints
C: ground joints
D: soldered joint
A: finished joints
B: welded joints
C: ground joints
D: soldered joint
举一反三
- There are three types of joints_______________________ A: fibrous joints. B: synovial joints C: cartilaginous joints D: flexible joints
- The most common of joints are corner blocks, doubled-doweljoints, dovetail joints, miter joints, and mortise and tenon joints.
- Emulsion oils and sodium nitrite are both approved additives， but the latter cannot be used if any pipes are （） or if any soldered joints exit.
- Inflammation of joints is termed as ______.
- a long section of track without joints A: dedicated line B: curve radius C: continuous welded rail