Made by AIGNEP, it is a Nickel Plated Brass Y Connector with female thread all round, BSPP Parallel.
Made By AIGNEP, it is a Nickel Plated Brass Y connector Female / Female/ BSPT Male Thread.

Check your pipe threads before you order!

In Great Britain BSP British Standard Pipe threads are commonly used. These are either parallel (BSPP) which normally seal on a washer or 'O' ring seal, or tapered (BSPT) which taper along their length and normally seal by two mating threads and/ or tape.

How to measure your thread:

Use a tape rule or (vernier gauge) to measure across the outside of the male thread. Note that a thread that measures 0.5" is not 1/2" BSP thread!

Using the table below we can see that 0.5" is actually 1/4" BSP thread. Similarly, a thread that measures 1.0" is actually 3/4" BSP thread.


BSP Size Max. diameter min. diameter Thread pitch
  mm inch mm inch (mm)        TPI
1/16" 7.723 0.304 6.561 0.258 28
1/8" 9.728 0.383 8.565 0.337 28
1/4" 13.157 0.518 11.445 0.451 19
3/8" 16.662 0.656 14.95 0.589 19
1/2" 20.955 0.825 18.633 0.734 14
5/8" 22.911 0.902 20.589 0.811 14
3/4" 26.441 1.041 24.12 0.95 14
1" 33.249 1.309 30.292 1.193 11
1 1/4" 41.91 1.65 38.953 1.534 11
1 1/2" 47.803 1.882 44.846 1.766 11
2" 59.614 2.347 56.657 2.231 11
2 1/2" 75.184 2.96 72.227 2.844 11
3" 87.884 3.46 84.927 3.344 11
4" 113.03 4.45 110.073 4.334 11
5" 138.43 5.45 135.472 5.334 11
6" 163.83 6.45 160.872 6.334 11