Gas Flexible Pipe and Joint

Overview

The flexible piping method has revolutionized the way gas pipes are installed and maintained. By using bendable flexible pipes and advanced joint technologies, this method offers enhanced adaptability and ease of use for modern gas piping solutions.

• Stabilized Sealing Performance: A structure that ensures consistent sealing even in the presence of minor defects like dents or scratches in the flexible tube.
• Suppression of Human Errors: The colored pressing wheel acts as a visual indicator, reducing errors in installation.
• Improved Constructability: No tools required, enhanced user feedback with a click feeling during insertion, and rotational flexibility post-installation.

Neo Joint Structure

The selected permeable material possesses waterproof characteristics while retaining breathability. In the event of accidental nailing, it allows gas to pass through the coating’s inner surface, serving as a mechanism to detect leaks caused by the nailing.

Applicable Range

• Type of Gas: City Gas & LP Gas
• Pressure: Less than 15kPa

New Installation

Double Floor Piping Method for Double Flooring

Piping Method for Ceiling

Extention

Extention for Outdoor Piping

Piping Tools for Flexible Pipe

Handling of Flexible Pipe

1. NOTES FOR PIPING WORKS

Be sure to conform to the following items in order to work the flexible pipe correctly and safely.

Restriction

1. Restricted usage The flexible pipe is exclusively for gas. Be sure absolutely not to use water, oil, hot water, and so forth.
2. Working area The flexible pipe is to be used for general low-pressure gas piping less than 0.1MPa(lkgf/cm2).
3. Restricted area Piping is prohibited in the following area
   1. The area where subject to possibly high temperature and high pressure
   2. The area where fixing of the flexible pipe or the piping mold cannot be achieved at the extension
   3. The area where the flexible pipe possibly suffers damage at changing container (in case of LP gas)
   4. The area where the piping most likely will be stomped and broken by persons or cars
   5. The area where the piping is subject to suffer vibration or impact
   6. The underground concrete of the direct buried base
   7. The area where the piping may touch the cable wire or electric wiring

Notes for handling flexible pipe

1. Be sure to bend the flexible pipe less than the radius prescribed, conforming to the minimum bending radius (Refer to P.6)
2. Be sure not to twist or pull the pipe.
3. Be sure not to apply severe impact nor stomp pipe
4. Be sure not to touch the cut area of the pipe to prevent becoming deformed, damaged, contaminated, and so forth. Also, be sure to take care as it may cause damage to your body.

2. NOTES FOR STORAGE

In order to avoid deforming or damaging the flexible pipe owing to the deficiency during storing the pipe, be sure to note the following items.

1. The storing of the Flexible pipe is generally indoors where subject to avoid rain.
2. The storing must be in the case and avoid loading heavy objects (that the case will be broken).
3. Be sure to avoid storing where subject to high temperature.

3. NOTES FOR TRANSPORTAION

In order to avoid deforming or damaging the flexible pipe owing to the deficiency during transporting the pipe, be sure to note the following items.

1. Throwing down is strictly prohibited. Be sure to handle it with care.
2. Be sure to avoid stacking heavy matters.
3. Be sure to avoid a strong impact.

4. INSPECTION

Upon piping works, be sure to check the external appearance.
In case the flexible pipe is deformed or damaged, be sure to use the pipe by removing such part.
In case it happens to be worked leaving such defects and left as it is, it may cause gas leak
accidents and be quite dangerous. Extra care must be taken to inspect for such cases of long-term storage or transportation, and there is a possibility of rough handling during work.

5. AIRTIGHT TEST

Be sure to perform the airtight test designated by related bills and/or regulations after finishing the piping works.

HANDLING CAUTION ITEMS/PROHIBITED ITEMS

• Be sure not to throw or drop the joints. (Parts may be broken and subject to contamination.)
• Be sure not to dismantle or modify the joints.
• Be sure not to re-use the joints.
• Be sure to confirm before piping works that there is no foreign matter inside the joints.
• Be sure to use a spanner, a mechanical wrench for flexible pipe, or a monkey wrench when screwing in the joints. (Using a pipe wrench is prohibited as the joints may be deformed.)
• Be sure to conform to the related laws, standards, procedures, and manuals.

SELECTION OF FLEXIBLE PIPE DIAMETER

The diameter of each piping is decided by pressure loss.

• The pressure loss indicated in the following diagrams designates pressure loss of air, and the effect from the bending (one bend for a 2-meter flexible pipe; bending radius R=50mm) is counted in advance. 
• In the case of actual gas, by converting the designed gas flow into the airflow adopting the following formula, read the amount of pressure loss at the airflow from the flexible pipe pressure loss diagram.

Qair √S x Qgas

Qair: Airflow (m^3/h)

Qgas: Designed gas flow(m^3/h)

S: Specific gravity of gas (Air=1)

PRESSURE LOSS DIAGRAM OF FLEXIBLE PIPE DIAMETER

PIPING DISTANCE  OF LP GAS

Please see the below-indicated table for LP gas as a reference.

Prohibited Area for Piping

Be sure to install the flexible pipe on the low-pressure area up to the gas plug. Piping works are prohibited on the below mentioned area.

Restricted Area to Use

FLEXIBLE PIPE IS ONLY USED UP TO GAS PLUG!

The flexible pipe can be used only up to the gas plug. Also, as the flexible pipe may be damaged, the usage where subject to be moved or vibration must not be applied.

Instructions for Use

Neo Joint

1. Preparation of flexible pipe

• Straighten the flexible pipe to be connected. (more than 10cm from the end)

CAUTION

• Be sure to make the flexible pipe straight.
• Be sure to make the pipe straight before cutting, as there may be difficult to make the pipe straight after cutting.
  

2. Peeling off the flexible pipe coating

• Peel off the coating of the end of flexible pipe for 7cm.

CAUTION

• It is normally impossible to cut the flexible pipe if the peeling length is too short.

• Be sure to take care of burrs on the cut area of the flexible pipe when pulling out the peeled coating.

3. Cutting flexible pipe

• Be sure to use an exclusive pipe cutter for flexible pipe.
• Be sure to cut the flexible pipe leaving 8 tops from the coated end.

CAUTION

• Be sure to cut the flexible pipe after straightening.
• Be sure to ascertain the flexible pipe being peeled off 8 tops.

4. Visual inspection of the cut section

• Check if there is no burr, turn-up, dent, and so forth on the cut section, and also if they are not flattened or smashed.

CAUTION

• In case of failure at the visual inspection, start again from the procedure no.1.
• In case the flexible pipe is bent, be sure to make the pipe straight.

5. Marking to the flexible pipe

• a. Hook the end of the marking tool to the tip of the flexible pipe.
• b. Mark with an oily marking pen (magic ink marker etc.) by fully filling the L-shape aperture of the marking tool.
• c. Be sure to carry out marking to 2 places in order to facilitate the check after connection.

CAUTION

• Be sure to carry out the marking with the flexible pipe being straight.

• Be sure to confirm the size display of the marking tool and carry out marking according to the size of the flexible pipe.

• In case of connecting in height or narrow place, be sure to elaborate a plan such as increasing the marking more clearly.

When the flexible pipe is cut leaving 8 tops, the upper end of the marking aperture and the coating top position are almost met.

6. Confirmation of marking

• Be sure to confirm the marking is not applied on the original flexible pipe.
• In case there is a marking on the original pipe, reconfirm the number of tops.

CAUTION

• Excessive tops may cause corrosion on the flexible pipe, due to lessened water-proof ability between the joint and the flexible pipe.

7. 1nserting flexible pipe into Neo Joint

• Make the flexible pipe straight.
• Insert the flexible pipe straight into the joint until the coating comes inside.
• Push the flexible pipe straight into the joint until it hits the rearmost. (The degree of pushing can be confirmed by the click feeling.)
• Be sure to confirm the marking is not visible.

CAUTION

• Be sure to ascertain that 8 tops of coating are peeled off. (With less than 7 tops being peeled off, the correct insertion cannot
  be achieved.).

• Be sure to ascertain the spacer is not detached from the joint.

• Be sure to insert the flexible pipe straight.

• In case the flexible pipe is short, insert the pipe gripping so hard that the coating does not come off.

In case that abnormality occurs when inserting the flexible pipe such as not smooth and the like, extract the flexible pipe again,  and after executing 4. Visual inspection and regaining the conditions of the pipe, then insert the pipe again straight.

8. Removing the spacer

• Carry out the removal of the spacer after the flexible pipe is inserted correctly.

CAUTION

• Be sure not to remove the spacer until this procedure

9. Pushing in the pressing-ring

• a. Push the pressing ring intently until it hits the body.
• b. Confirm the colored part of the pressing ring is not visible.
• c. Confirm the marking is visible.

CAUTION

If unusual results happen such as the pressing ring cannot be inserted smoothly, implement the following A, B, C, and D procedures and connect again from the procedure described in 6.

• A: Return the pressing ring to the position before pushing in.
• B: Provide the spacer in the original position.
• C: Pull out the flexible pipe from the Neff Joint.
• D: Confirm the end and the peeled-off length of the flexible pipe.

After confirming that the pipe is cut by 8 tops and in correct conditions, insert the flexible pipe again and then pushing the pressing-ring in.

10. Confirming the connection

• After pushing the pressing ring in, confirm that the flexible pipe and the pressing ring won’t be pulled out by pulling the flexible pipe.
• Confirm that the pipe moves slightly to the axis direction.
• In that case, confirm that the marking is L-shape.

CAUTION

• Pull the flexible pipe without grasping the pressing-ring.
• In case the flexible pipe is shod, care must be taken for the coating not be off.
• After completed the connection, the flexible pipe can be rotated and also moved slightly in axis direction.

Airtight Inspection

After completing the works, be sure to carry out the airtight inspection by the prescribed pressure and the method, to confirm there is no leaking.

Neo Joint

1. Preparation of flexible pipe

• Straighten the flexible pipe to be connected. (more than 10cm from the end)

CAUTION

• Be sure to make the flexible pipe straight.
• Be sure to make the pipe straight before cutting, as there may be difficult to make the pipe straight after cutting.
  

2. Peeling off the flexible pipe coating

• Peel off the coating of the end of flexible pipe for 7cm.

CAUTION

• It is normally impossible to cut the flexible pipe if the peeling length is too short.

• Be sure to take care of burrs on the cut area of the flexible pipe when pulling out the peeled coating.

3. Cutting flexible pipe

• Be sure to use an exclusive pipe cutter for flexible pipe.
• Be sure to cut the flexible pipe leaving 8 tops from the coated end.

CAUTION

• Be sure to cut the flexible pipe after straightening.
• Be sure to ascertain the flexible pipe being peeled off 8 tops.

4. Visual inspection of the cut section

• Check if there is no burr, turn-up, dent, and so forth on the cut section, and also if they are not flattened or smashed.

CAUTION

• In case of failure at the visual inspection, start again from the procedure no.1.
• In case the flexible pipe is bent, be sure to make the pipe straight.

5. Inserting pressing ring

• Insert the pressing-ring into the flexible pipe.

6. Fixing the retainer

• Hook the metal claw of the retainer to the first trough.

CAUTION

• Be sure not to fix the retainer adversely, as the push-ring cannot be tightened.
• Be sure not to fix the metal claw of the retainer to the second trough (wrong number of tops), as the push-ring cannot be tightened.

7. Inserting to the main

• Insert the flexible pipe fixed with the pressing ring and the retainer to the main, and tighten with your hand.

8. Tightening the pressing-ring

• Tighten the pressing ring with a wrench until it hits the main.

Airtight Inspection

After completing the works, be sure to carry out the airtight inspection by the prescribed pressure and the method, to confirm there is no leaking.

Note at Airtight Inspection

CAUTION

• Be sure to make the flexible pipe straight.
• Be sure to make the pipe straight before cutting, as there may be difficult to make the pipe straight after cutting.