| 摘要 |
FIELD: building, particularly vertical solid waste transportation in building and building structure by gravity. ^ SUBSTANCE: refuse chute shaft comprises at least two three-layered pipes to be installed along common vertical axis. Inner and outer steel pipes are formed by spiral wound lock-seaming operation. Seam of inner pipe faces outwards and has bent folded upwards. Seam of outer pipe faces inwards. ^ EFFECT: increased reliability and service life of connection between shaft layers and air-tight connection of three-layered pipes one with another along common vertical axis. ^ 2 cl, 2 dwg |
