These are 90 Degree Water Check Valves which can be threaded straight into boilers for injector/water pump feed etc. 

They are as follows: 

1/4 BSP x available in 3/8, 5/16 or 1/4 Pipe

1/2 x 26tpi available in 3/8, 5/16 or 1/4 Pipe

7/16 x 26tpi x 1/4 Pipe

3/8 x 32tpi x 1/4 Pipe

5/16 x 32tpi x 3/16 Pipe

1/4 x 40tpi x 1/8 or 5/32 Pipe

3/16 x 40tpu x 3/32 Pipe

These are manufactured items, so please allow up to 7 days for delivery.