Below are listed all the relief valves in API-526 (Size ", Orifice and dimensions, to complete your design all you require is the size, orifice and type either Spring or Pilot available from the PID or Instrument Engineer(check inlet flange bolt lengths))
1" x 2"
1D2 150# x 150# Spring Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1D2 150# x 150# Pilot Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1D2 300# x 150# Spring Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1D2 300# x 150# Pilot Relief Valve 4-3/8 Inlet x 4-1/2 Outlet
1D2 600# x 150# Spring Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1D2 600# x 150# Pilot Relief Valve 4-3/8 Inlet x 4-1/2 Outlet
1D2 900# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1D2 1500# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1D2 2500# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1E2 150# x 150# Spring Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1E2 150# x 150# Pilot Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1E2 300# x 150# Spring Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1E2 300# x 150# Pilot Relief Valve 4-3/8 Inlet x 4-1/2 Outlet
1E2 600# x 150# Spring Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1E2 600# x 150# Pilot Relief Valve 4-3/8 Inlet x 4-1/2 Outlet
1E2 900# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1E2 1500# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1E2 2500# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1F2 150# x 150# Pilot Relief Valve 4-1/8 Inlet x 4-1/2 Outlet
1F2 300# x 150# Pilot Relief Valve 4-3/8 Inlet x 4-1/2 Outlet
1F2 600# x 150# Pilot Relief Valve 4-3/8 Inlet x 4-1/2 Outlet
1F2 900# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1F2 1500# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1F2 2500# x 300# Pilot Relief Valve 4-15/16 Inlet x 4-3/4 Outlet
1 1/2" x 2"
1 1/2D2 150# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2D2 300# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2D2 600# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2D2 900# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2D2 900# x 300# Spring Relief Valve 4-1/8 Inlet x 5-1/2 Outlet
1 1/2D2 1500# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2D2 1500# x 300# Spring Relief Valve 4-1/8 Inlet x 5-1/2 Outlet
1 1/2D2 2500# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2E2 150# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2E2 300# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2E2 600# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2E2 900# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2E2 900# x 300# Spring Relief Valve 4-1/8 Inlet x 5-1/2 Outlet
1 1/2E2 1500# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2E2 1500# x 300# Spring Relief Valve 4-1/8 Inlet x 5-1/2 Outlet
1 1/2E2 2500# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2F2 150# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2F2 150# x 150# Spring Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2F2 300# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2F2 300# x 150# Spring Relief Valve 4-7/8 Inlet x 6- Outlet
1 1/2F2 600# x 150# Pilot Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2F2 600# x 150# Spring Relief Valve 4-7/8 Inlet x 6- Outlet
1 1/2F2 900# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2F2 1500# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2F2 2500# x 300# Pilot Relief Valve 5-7/8 Inlet x 5-1/2 Outlet
1 1/2F2 (4) 300# x 150# Spring Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2" x 3"
1 1/2D3 2500# x 300# Spring Relief Valve 5-1/2 Inlet x 7- Outlet
1 1/2E3 2500# x 300# Spring Relief Valve 5-1/2 Inlet x 7- Outlet
1 1/2F3 900# x 300# Spring Relief Valve 4-7/8 Inlet x 6-1/2 Outlet
1 1/2F3 1500# x 300# Spring Relief Valve 4-7/8 Inlet x 6-1/2 Outlet
1 1/2F3 2500# x 300# Spring Relief Valve 5-1/2 Inlet x 7- Outlet
1 1/2G3 150# x 150# Spring Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2G3 150# x 150# Pilot Relief Valve 5-1/8 Inlet x 4-7/8 Outlet
1 1/2G3 300# x 150# Spring Relief Valve 4-7/8 Inlet x 6- Outlet
1 1/2G3 300# x 150# Pilot Relief Valve 5-1/8 Inlet x 4-7/8 Outlet
1 1/2G3 600# x 150# Spring Relief Valve 4-7/8 Inlet x 6- Outlet
1 1/2G3 600# x 150# Pilot Relief Valve 5-1/8 Inlet x 4-7/8 Outlet
1 1/2G3 900# x 150# Spring Relief Valve 4-7/8 Inlet x 6-1/2 Outlet
1 1/2G3 900# x 300# Pilot Relief Valve 6-3/8 Inlet x 6-3/4 Outlet
1 1/2G3 1500# x 300# Pilot Relief Valve 6-3/8 Inlet x 6-3/4 Outlet
1 1/2G3 2500# x 300# Pilot Relief Valve 6-3/8 Inlet x 6-3/4 Outlet
1 1/2G3 (4) 300# x 150# Spring Relief Valve 4-7/8 Inlet x 4-3/4 Outlet
1 1/2H3 150# x 150# Spring Relief Valve 5-.125 Inlet x 4-.875 Outlet
1 1/2H3 150# x 150# Pilot Relief Valve 5-1/8 Inlet x 4-7/8 Outlet
1 1/2H3 300# x 150# Spring Relief Valve 5-.125 Inlet x 4-.875 Outlet
1 1/2H3 300# x 150# Pilot Relief Valve 5-1/8 Inlet x 4-7/8 Outlet
1 1/2H3 600# x 150# Pilot Relief Valve 5-1/8 Inlet x 4-7/8 Outlet
1 1/2H3 900# x 300# Pilot Relief Valve 6-3/8 Inlet x 6-3/4 Outlet
1 1/2H3 1500# x 300# Pilot Relief Valve 6-3/8 Inlet x 6-3/4 Outlet
1 1/2H3 2500# x 300# Pilot Relief Valve 6-3/8 Inlet x 6-3/4 Outlet
2" x 3"
2G3 150# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2G3 300# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2G3 600# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2G3 900# x 300# Pilot Relief Valve 6-9/16 Inlet x 6-3/4 Outlet
2G3 1500# x 150# Spring Relief Valve 6-1/8 Inlet x 6-3/4 Outlet
2G3 1500# x 300# Pilot Relief Valve 6-9/16 Inlet x 6-3/4 Outlet
2G3 2500# x 150# Spring Relief Valve 6-1/8 Inlet x 6-3/4 Outlet
2G3 2500# x 300# Pilot Relief Valve 7- Inlet x 6-3/4 Outlet
2H3 150# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2H3 300# x 150# Spring Relief Valve 5-.125 Inlet x 4-.875 Outlet
2H3 300# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2H3 600# x 150# Spring Relief Valve 6-.0625 Inlet x 6-.375 Outlet
2H3 600# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2H3 900# x 150# Spring Relief Valve 6-.0625 Inlet x 6-.375 Outlet
2H3 900# x 300# Pilot Relief Valve 6-9/16 Inlet x 6-3/4 Outlet
2H3 1500# x 300# Spring Relief Valve 6-.0625 Inlet x 6-.375 Outlet
2H3 1500# x 300# Pilot Relief Valve 6-9/16 Inlet x 6-3/4 Outlet
2H3 2500# x 300# Pilot Relief Valve 7- Inlet x 6-3/4 Outlet
2J3 150# x 150# Spring Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2J3 150# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2J3 300# x 150# Spring Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2J3 300# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2J3 600# x 150# Pilot Relief Valve 5-3/8 Inlet x 4-7/8 Outlet
2J3 900# x 300# Pilot Relief Valve 6-9/16 Inlet x 6-3/4 Outlet
2J3 1500# x 300# Pilot Relief Valve 6-9/16 Inlet x 6-3/4 Outlet
2J3 2500# x 300# Pilot Relief Valve 7- Inlet x 6-3/4 Outlet
3" x 4"
3J4 150# x 150# Pilot Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3J4 300# x 150# Spring Relief Valve 7-1/4 Inlet x 7-1/8 Outlet
3J4 300# x 150# Pilot Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3J4 600# x 150# Spring Relief Valve 7-1/4 Inlet x 7-1/8 Outlet
3J4 600# x 150# Pilot Relief Valve 6-3/8 Inlet x 6-3/8 Outlet
3J4 900# x 150# Spring Relief Valve 7-1/4 Inlet x 7-1/8 Outlet
3J4 900# x 300# Pilot Relief Valve 7-1/ 2 Inlet x 7-1/8 Outlet
3J4 1500# x 300# Spring Relief Valve 7-1/4 Inlet x 7-1/8 Outlet
3J4 1500# x 300# Pilot Relief Valve 7-1/ 2 Inlet x 7-1/8 Outlet
3K4 150# x 150# Spring Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3K4 150# x 150# Pilot Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3K4 300# x 150# Spring Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3K4 300# x 150# Pilot Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3K4 600# x 150# Spring Relief Valve 7-1/4 Inlet x 7-1/8 Outlet
3K4 600# x 150# Pilot Relief Valve 6-3/8 Inlet x 6-3/8 Outlet
3K4 900# x 300# Pilot Relief Valve 7-1/2 Inlet x 7-1/8 Outlet
3K4 1500# x 300# Pilot Relief Valve 7-1/2 Inlet x 7-1/8 Outlet
3K6 900# x 150# Spring Relief Valve 7-13/16 Inlet x 8-1/2 Outlet
3K6 1500# x 300# Spring Relief Valve 7-3/4 Inlet x 8-1/2 Outlet
3L4 150# x 150# Spring Relief Valve 6-1/8 Inlet x 6-1/2 Outlet
3L4 150# x 150# Pilot Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3L4 300# x 150# Spring Relief Valve 6-1/8 Inlet x 6-1/2 Outlet
3L4 300# x 150# Pilot Relief Valve 6-1/8 Inlet x 6-3/8 Outlet
3L4 600# x 150# Pilot Relief Valve 6-3/8 Inlet x 6-3/8 Outlet
3L4 900# x 300# Pilot Relief Valve 7-1/2 Inlet x 7-1/8 Outlet
3L4 1500# x 300# Pilot Relief Valve 7-1/2 Inlet x 7-1/8 Outlet
4" x 6"
4L6 150# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4L6 300# x 150# Spring Relief Valve 7-1/16 Inlet x 7-1/8 Outlet
4L6 300# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4L6 600# x 150# Spring Relief Valve 7-1/16 Inlet x 8- Outlet
4L6 600# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4L6 900# x 150# Spring Relief Valve 7-3/4 Inlet x 8-3/4 Outlet
4L6 900# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4L6 1500# x 150# Spring Relief Valve 7-3/4 Inlet x 8-3/4 Outlet
4L6 1500# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4M6 150# x 150# Spring Relief Valve 7- Inlet x 7-1/4 Outlet
4M6 150# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4M6 300# x 150# Spring Relief Valve 7- Inlet x 7-1/4 Outlet
4M6 300# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4M6 600# x 150# Spring Relief Valve 7- Inlet x 8- Outlet
4M6 600# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4M6 900# x 150# Spring Relief Valve 7-3/4 Inlet x 8-3/4 Outlet
4M6 900# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4M6 1500# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4N6 150# x 150# Spring Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4N6 150# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4N6 300# x 150# Spring Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4N6 300# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4N6 600# x 150# Spring Relief Valve 7-3/4 Inlet x 8-3/4 Outlet
4N6 600# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4N6 900# x 150# Spring Relief Valve 7-3/4 Inlet x 8-3/4 Outlet
4N6 900# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4N6 1500# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4P6 150# x 150# Spring Relief Valve 7-1/8 Inlet x 9- Outlet
4P6 150# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4P6 300# x 150# Spring Relief Valve 8-7/8 Inlet x 10- Outlet
4P6 300# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4P6 600# x 150# Spring Relief Valve 8-7/8 Inlet x 10-0 Outlet
4P6 600# x 150# Pilot Relief Valve 7-3/4 Inlet x 8-1/4 Outlet
4P6 600# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4P6 900# x 150# Spring Relief Valve 8-7/8 Inlet x 10- Outlet
4P6 900# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4P6 1500# x 300# Pilot Relief Valve 9-13/16 Inlet x 9-3/16 Outlet
4P6 1500# x 600# Pilot Relief Valve 9-13/16 Inlet x 10-3/8 Outlet
4P6 (4) 300# x 150# Spring Relief Valve 7-1/8 Inlet x 9- Outlet
6" x 8"
6Q8 150# x 150# Spring Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6Q8 150# x 150# Pilot Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6Q8 300# x 150# Spring Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6Q8 300# x 150# Pilot Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6Q8 600# x 150# Spring Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6Q8 600# x 150# Pilot Relief Valve 9-11/16 Inlet x 9-1/2 Outlet
6Q8 600# x 300# Pilot Relief Valve 9-11/16 Inlet x 10-7/16 Outlet
6R8 150# x 150# Spring Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6R8 150# x 150# Pilot Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6R8 300# x 150# Spring Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6R8 300# x 150# Pilot Relief Valve 9-7/16 Inlet x 9-1/2 Outlet
6R8 600# x 150# Pilot Relief Valve 9-11/16 Inlet x 9-1/2 Outlet
6" x 10"
6R10 300# x 150# Spring Relief Valve 9-7/16 Inlet x 10-1/2 Outlet
6R10 600# x 150# Spring Relief Valve 9-7/16 Inlet x 10-1/2 Outlet
8" x 10"
8T10 150# x 150# Spring Relief Valve 10-7/8 Inlet x 11- Outlet
8T10 150# x 150# Pilot Relief Valve 10-7/8 Inlet x 11- Outlet
8T10 300# x 150# Spring Relief Valve 10-7/8 Inlet x 11- Outlet
8T10 300# x 150# Spring Relief Valve 10-7/8 Inlet x 11- Outlet
8T10 300# x 150# Pilot Relief Valve 10-7/8 Inlet x 11- Outlet
8T10 600# x 150# Pilot Relief Valve 11-11/16 Inlet x 11- Outlet