68，air temperature vaporizer of lng system -威尼斯2299

air temperature vaporizer of lng system

1.the low temperature process pipe in front of air temperature gasifier of 1 lng system is made of 06cr19ni10 seamless stainless steel pipe (gb / t14976-2002) for conveying fluid. the other normal temperature pipes are made of 16mn, 20 ᦇ steel (gb / t8163) or q235b (gb / t13973-92) seamless steel pipes for conveying fluid. the branch pipes of pneumatic control valves are made of copper pipes ∮ 6 * 1.5, and the main pipes are made of seamless steel pipes.

2. the equipment insulation and installation shall be in accordance with the requirements of the supplier. after rust removal, the external surface of non insulated overhead process pipeline shall be painted with two layers of antirust primer and two layers of mixed finish (stainless steel pipe of cng system may not be painted), and the pipeline support shall be curved groove sliding support (see standard atlas 97r403.003 for details); the insulation layer of overhead low temperature pipeline is made of composite polyethylene material (ccpe), and its support is polyurethane pipeline support, with the thickness of pipeline insulation layer of 100 mm. polytetrafluoroethylene curved plate is used as sliding support between overhead pipeline and support of process pipeline 3x, 4x gas phase pipeline and its branch pipe; the overhead hot water circulating pipe is insulated with rock wool pipe shell with thickness of 30mm and coated with color steel plate; the buried hot water pipeline adopts "prefabricated directly buried insulation pipe", and the insulation layer material is polyurethane.

3. the flange connection of normal temperature process pipeline (pn ≤ 1.6mpa) adopts flat welded steel pipe flange, and the material is 20 # steel; flexible graphite composite gasket is used for flange sealing gasket, and the gasket size is corresponding to the sealing surface of matching flange; the fasteners are commercial grade studs and nuts, the double head nuts are grade b and the performance grade is 8.8, and the nuts are type i hexagon nuts with the performance grade of 8; the pipe fittings are all seamless stamping pipe fittings, the material is 20 # steel, and the elbow radius is 1.5dn.

4. the flange connection of lng cryogenic process pipeline is made of raised face and neck butt welded steel pipe flange, and the material is 06cr19ni10; the flange sealing gasket adopts metal spiral wound gasket (06cr19ni10); special double head stud and nut (06cr19ni10) are used for fasteners; seamless stamping pipe fittings are used, material is 06cr19ni10, elbow radius is 3dn.

5. the weld surface of socket welding and fillet welding of process pipeline is inspected by liquid penetration, and the butt weld is inspected by radiography. the weld quality is no less than ii, and the flaw detection rate of stainless steel pipeline welding seam is 100%.