Abstract: A heat exchanger having excellent heat exchanging performance is obtainable by a simple production technique and at a low cost. This is achieved by providing a fin member and by increasing heat conductivity between the fin member and a meandering pipe body. Further, the heat exchanger is made compact for high degrees of layout freedom, enabling the heat exchanger to be installed in a tight space. Engagement grooves (8) are provided in both end surfaces (6, 7), which are opposite to each other, of a fin member (5) in which fins (4) are parallel arranged. Straight pipe sections (2) are parallelly arranged, with gaps (16)in between, in the engagement grooves (8) of the fin member (5). The straight pipe sections (2)a are connected at bent sections (3). A pair of meandering sections (11, 12) is arranged opposite to each other with an insertion gap (17) of the fin member (5) in between.

Abstract: A heat exchanger having excellent heat exchanging performance is obtainable by a simple production technique and at a low cost. This is achieved by providing a fin member and by increasing heat conductivity between the fin member and a meandering pipe body. Further, the heat exchanger is made compact for high degrees of layout freedom, enabling the heat exchanger to be installed in a tight space. Engagement grooves are provided in both end surfaces, which are opposite to each other, of a fin member in which fins are parallel arranged. Straight pipe sections are parallelly arranged, with gaps in between, in the engagement grooves of the fin member. The straight pipe sections a are connected at bent sections. A pair of meandering sections is arranged opposite to each other with an insertion gap of the fin member in between. On of the meandering sections and the other meandering section are connected by a connection pipe to form a meandering pipe main body.

Abstract: A joint for piping includes a pipe with an annular swelling wall and a connector body with a socket that includes locking pieces. The locking pieces hold the annular swelling wall when the pipe is inserted through the connector body to connector the pipe to the connector body. A projected member on the pipe fits in a recess on the connector body to prevent rotation between the pipe and the connector body.

Abstract: A joint for piping includes a pipe with an annular swelling wall and a connector body with a socket that includes locking pieces. The locking pieces hold the annular swelling wall when the pipe is inserted through the connector body to connector the pipe to the connector body. A projected member on the pipe fits in a recess on the connector body to prevent rotation between the pipe and the connector body.