081 Precautions Working pressure differs by temperature and size. Use within an allowable range of relationship between maximum working pressure and temperature. Avoid using them for instant heater. If the instant heater breaks down or has a malfunction, water or steam of abnormal temperature may flow and damage piping. Do not use them for piping draining from the steam convection oven, one of kitchen equipment. Detergents used in steam convection oven may contain ingredients that would give a negative influence (cracking, water leakage, etc.) to pipes and fittings. U-bands (with rubber seat) are recommended for fixing piping. In the case of using U-bolts inevitably, provide a cushion such as rubber to prevent the pipes from touching the hardware directly. Cushion saddles and U-bolt rails are available as a cushion material. Please consider using them. Be cautious not to tighten nuts excessively. As a reference of nut tightening, �@ tighten by hand and then rotate 1/2 using a spanner, etc., or �A tighten by setting torque wrench at 1N・m (10kgf・cm). Since AV C-PVC pipes have a higher heat expansion/contraction amount compared to steel pipes, an expansion/contraction treatment is important. Not performing an expansion/contraction treatment could cause damage. Provide a treatment to absorb expansion/contraction using AV expansion joints or elbows, etc. Avoid using AV C-PVC pipes for burring under concrete or mortar. In the case of using for chemical solution piping, please consult our nearest office whether or not it is usable in advance. When using as piping for high-rise architectural structure such as buildings, consider not only the pump pressure but also the influence of the water head pressure (height) and use within a range of allowable relationship between maximum working temperature and pressure. If securing space for sufficient expansion/contraction measure is difficult, do not use AV C-PVC pipes and consider using other types of pipes (copper pipes, lining steel pipes, metal reinforced double laminated pipes, cross-linked polyethylene pipes, etc.) * Vertical piping, buried piping, etc. are examples of places where implementing an expansion/contraction measure is difficult. Fittings that use a rubber ring to tighten pipes cannot be used. Working Pressure vs. Temperature Use for Hot Water Equipment Use for Industrial Kitchen Drainage Piping Piping to Architectural Structure Piping Under Concrete Use for Chemical Solution Piping Use of Rubber Ring Joint Piping Support/Fixation Expansion/Contraction Treatment Water heater Caution Design Can I use this chemical solution? For branching out from the main pipe side, the stress generated by expansion/contraction of the main pipe shall not be focused on the fitting of a branch point. For the purpose of branching method, basic items requiring an extra attention are as follows. ・ Never execute direct branching and avoid having expansion/contraction of the main pipe give an impact to the branch pipe side by placing an elbow. ・ Locate a branch point of the main pipe near a fix point as much as possible. Expansion/Contraction Absorption at Branch Area Loose support Expansion Joint Loose support Expansion Joint Tee Fixing support Loose support Fixing point Elbow Elbow 0.5 ｍ or more 2ｍ or less 0.3 ｍ or more × Fitting Type Size Expansion/Contraction Absorption Amount Implementation example (absorbable expansion/contraction length) AV Expansion Joint 20 mm to 100 mm (Size 20 to 75 mm) 80 mm (Size 100 mm) 100 mm Elbow 13 mm to 200 mm ― Fixation Loose Loose Fixation 20 to 75mm：14ｍ or less 100mm：18ｍ or less 0.5 ｍ or less 0.5 ｍ or less Fixation Loose Fixation ４ ｍ or less ４ ｍ or less 0.5 to 2 ｍ 0.5 ｍ or more 0.5 ｍ or more ２ ｍ or less 0.5 ｍ to 1 ｍ ２ ｍ or less ２ ｍ or less Use to absorb expansion/contraction at a straight part. . When length of the straight part is over 4 m * In the case of temperature difference of 70℃ or less. Use to absorb expansion/contraction at a bending part. . When length of the straight part is 2 m or less .When length of the straight part is 2 up to 4 m * Also refer to [Piping Support/Fixation]. Multi-Branching Piping Avoid using AV C-PVC pipes for multi-branching piping in bath, etc. and consider using lining steel pipes, etc. Caution Caution Caution Caution Caution Caution Caution Caution Caution Warning Squared timber U-bolts Rubber sheet Rubber sheet C-PVC Pipe Saddle hand Angle C-PVC Pipe Cushion saddles and U-bolt rails C-PVC Pipe Precautions