Helps leads a 27-strong playing squad, one which will be hoping to emulate the success of last year's tour.
The Wales Under 18's trips to South Africa are a vital tool in giving young players the chance to experience the preparation which comes with international rugby. Many of the Wales Under 20 squad which reached the final of this summer's Junior World Championship in France had previously toured South Africa with the Under 18's.
Dafydd Howells, who travelled to South Africa last year with Wales Under 18's, went on to make his senior Wales debut against Japan less than a year later.
And with a number of talented young players in his squad this time around, Lewis will be hoping some of them can go on to emulate Howells' development.
Helps is one of eight Scarlets players in the squad with regional teammates Torin Myhill, Tom Phillips and Ryan Elias joining him in the pack.
Behind the scrum, Lewis has plenty of firepower at his disposal with the likes of Aled Summerhill, Ashton Hewitt and Tyler Morgan all providing an attacking threat.
Summerhill, who gained British & Irish Cup experience with Pontypridd last season, is one of four centres in the squad while Angus O'Brien, Luke Price and Dan Jones will compete for the fly-half spot.
"We are pleased with the squad we have available for this trip," said Wales Under 18 team manager Phil John.
"It's vital we give these young players a taste of international rugby and while we'll be giving it our all to win all three games, what's more important for us is how we play the game.
"We've got some quick, exciting backs and we'll be looking to give them as much ball as possible to see what they can do."
First up for Wales is a clash with France on August 9 before a meeting with England in George just four days later. The tour then concludes against South Africa at the Boland Stadium in Wellington on August 17.
With three games in just over a week, John and the coaching staff know they will have to make the most of all 27 players on the tour.
"We've got confidence in every member of our squad and each player will get plenty of game time," said John.
"We face three top quality international sides and we expect the standard of rugby to be just that.
"The success of the Wales Under 20 side earlier this summer proves how vital these tours are as many of those players came to South Africa with us a few years ago.
"Hopefully this group can go on to achieve similar things but for now, we are firmly focussed on the challenges ahead."
Wales Under 18 squad for South Africa tour:
Backs: Steffan Evans (Scarlets), Josh Adams (Scarlets), Ashton Hewitt (Newport Gwent Dragons), Tyler Morgan (Newport Gwent Dragons), Aled Summerhill (Cardiff Blues), Garyn Smith (Cardiff Blues), Joe Thomas (Ospreys), Angus O'Brien (Newport Gwent Dragons), Luke Price (Ospreys), Dan Jones (Scarlets), Dan Brooks (Ospreys), Tom Williams (Cardiff Blues).
Forwards: Keagan Bale (Newport Gwent Dragons), Luke Garrett (Newport Gwent Dragons), Leon Crump (Cardiff Blues), Torin Myhill (Scarlets), Ryan Elias (Scarlets), Alex Jeffreys (Newport Gwent Dragons), Javan Sebastian (Scarlets), Adam Beard (Ospreys), Rory Thornton (Ospreys), Josh Helps (Scarlets & Captain), Oliver Hitchings (Cardiff Blues), Tom Phillips (Scarlets), Jon Fox (Ospreys), Jordan Collier (Ospreys), Oliver Griffiths (Newport Gwent Dragons).
Wales Under 18 fixtures:
• France: August 9, City Park Stadium, Athlone. Kick-off 14.00.
• England: August 13, Outeniqua Park, George. Kick-off 14.00.
• South Africa: August 17, Boland Stadium, Wellington. Kick-off 15.30.
All kick-off times are South African time.