i) Except as provided in 4-6-2/9.7.3(a)ii), the collision bulkhead may be pierced below the bulkhead deck by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a screwdown or butterfly valve capable of being operated from above the bulkhead deck; the valve chest being secured to the collision bulkhead inside the forepeak.